From abbed0f4549406352ded8d445be5e87de44035bc Mon Sep 17 00:00:00 2001
From: James Graham <james@hoppipolla.co.uk>
Date: Mon, 21 Nov 2022 19:31:48 +0000
Subject: [PATCH] Bug 1800456 - Add preconditions to css-view-transitions
 tests, r=emilio

This ensures that the tests don't just timeout when the feature isn't implemented.

Differential Revision: https://phabricator.services.mozilla.com/D162554
---
 .../meta/css/css-view-transitions/3d-transform-incoming.html.ini     | 2 +-
 .../meta/css/css-view-transitions/3d-transform-outgoing.html.ini     | 2 --
 .../css/css-view-transitions/content-smaller-than-box-size.html.ini  | 2 +-
 .../content-visibility-auto-shared-element.html.ini                  | 2 +-
 .../css-view-transitions/content-with-clip-max-texture-size.html.ini | 2 +-
 .../meta/css/css-view-transitions/content-with-clip-root.html.ini    | 2 +-
 .../meta/css/css-view-transitions/content-with-clip.html.ini         | 2 +-
 .../meta/css/css-view-transitions/content-with-inline-child.html.ini | 2 +-
 .../css-view-transitions/content-with-transform-new-image.html.ini   | 2 +-
 .../css-view-transitions/content-with-transform-old-image.html.ini   | 2 +-
 .../css-view-transitions/css-tags-paint-order-with-entry.html.ini    | 2 +-
 .../meta/css/css-view-transitions/css-tags-paint-order.html.ini      | 2 +-
 .../meta/css/css-view-transitions/css-tags-shared-element.html.ini   | 2 +-
 .../dialog-in-top-layer-during-transition-new.html.ini               | 2 +-
 .../dialog-in-top-layer-during-transition-old.html.ini               | 2 +-
 .../meta/css/css-view-transitions/element-with-overflow.html.ini     | 2 +-
 .../meta/css/css-view-transitions/far-away-capture.html.ini          | 2 +-
 .../css/css-view-transitions/hit-test-unpainted-element.html.ini     | 2 +-
 .../css/css-view-transitions/hit-test-unrelated-element.html.ini     | 2 +-
 .../meta/css/css-view-transitions/iframe-transition.sub.html.ini     | 2 +-
 .../input-blocked-when-rendering-suppressed.html.ini                 | 3 +--
 .../web-platform/meta/css/css-view-transitions/japanese-tag.html.ini | 2 +-
 .../meta/css/css-view-transitions/new-and-old-sizes-match.html.ini   | 2 --
 .../css/css-view-transitions/new-content-captures-clip-path.html.ini | 2 +-
 .../new-content-captures-different-size.html.ini                     | 2 +-
 .../css/css-view-transitions/new-content-captures-opacity.html.ini   | 2 +-
 .../meta/css/css-view-transitions/new-content-captures-root.html.ini | 2 +-
 .../new-content-container-writing-modes.html.ini                     | 2 +-
 .../css-view-transitions/new-content-element-writing-modes.html.ini  | 2 +-
 .../css/css-view-transitions/new-content-has-scrollbars.html.ini     | 2 +-
 .../css-view-transitions/new-content-intrinsic-aspect-ratio.html.ini | 2 +-
 .../meta/css/css-view-transitions/new-content-is-empty-div.html.ini  | 2 +-
 .../css/css-view-transitions/new-content-object-fit-fill.html.ini    | 2 +-
 .../css/css-view-transitions/new-content-object-fit-none.html.ini    | 2 +-
 .../new-content-object-view-box-clip-path-reference.html.ini         | 2 +-
 .../new-content-object-view-box-clip-path.html.ini                   | 2 +-
 .../new-content-object-view-box-overflow-clipped.html.ini            | 2 +-
 .../new-content-object-view-box-overflow.html.ini                    | 2 +-
 .../meta/css/css-view-transitions/new-content-scaling.html.ini       | 2 +-
 .../css-view-transitions/new-content-with-overflow-zoomed.html.ini   | 2 +-
 .../meta/css/css-view-transitions/new-content-with-overflow.html.ini | 2 +-
 .../meta/css/css-view-transitions/new-element-on-start.html.ini      | 2 +-
 .../css/css-view-transitions/new-root-vertical-writing-mode.html.ini | 2 +-
 .../no-containment-on-new-element-mid-transition.html.ini            | 3 +--
 .../css/css-view-transitions/no-containment-on-new-element.html.ini  | 3 +--
 .../css/css-view-transitions/no-containment-on-old-element.html.ini  | 3 +--
 .../no-css-animation-while-render-blocked.html.ini                   | 3 +--
 .../css/css-view-transitions/no-raf-while-render-blocked.html.ini    | 3 +--
 .../meta/css/css-view-transitions/no-root-capture.html.ini           | 2 +-
 .../meta/css/css-view-transitions/nothing-captured.html.ini          | 2 +-
 .../meta/css/css-view-transitions/object-view-box-new-image.html.ini | 2 +-
 .../meta/css/css-view-transitions/object-view-box-old-image.html.ini | 2 +-
 .../css/css-view-transitions/old-content-captures-clip-path.html.ini | 2 +-
 .../old-content-captures-different-size.html.ini                     | 2 +-
 .../css/css-view-transitions/old-content-captures-opacity.html.ini   | 2 +-
 .../meta/css/css-view-transitions/old-content-captures-root.html.ini | 2 +-
 .../old-content-container-writing-modes.html.ini                     | 2 +-
 .../css-view-transitions/old-content-element-writing-modes.html.ini  | 2 +-
 .../css/css-view-transitions/old-content-has-scrollbars.html.ini     | 2 +-
 .../css-view-transitions/old-content-intrinsic-aspect-ratio.html.ini | 2 +-
 .../meta/css/css-view-transitions/old-content-is-empty-div.html.ini  | 2 +-
 .../css/css-view-transitions/old-content-object-fit-fill.html.ini    | 2 +-
 .../css/css-view-transitions/old-content-object-fit-none.html.ini    | 2 +-
 .../old-content-object-view-box-clip-path-reference.html.ini         | 2 +-
 .../old-content-object-view-box-clip-path.html.ini                   | 2 +-
 .../old-content-object-view-box-overflow.html.ini                    | 2 +-
 .../css-view-transitions/old-content-with-overflow-zoomed.html.ini   | 2 +-
 .../meta/css/css-view-transitions/old-content-with-overflow.html.ini | 2 +-
 .../css/css-view-transitions/old-root-vertical-writing-mode.html.ini | 2 +-
 .../pseudo-computed-style-stays-in-sync-with-new-element.html.ini    | 3 +--
 .../meta/css/css-view-transitions/pseudo-get-computed-style.html.ini | 5 ++---
 .../css/css-view-transitions/root-captured-as-different-tag.html.ini | 2 +-
 .../root-scrollbar-with-fixed-background.html.ini                    | 2 +-
 .../css-view-transitions/root-style-change-during-animation.html.ini | 2 +-
 .../css/css-view-transitions/root-to-shared-animation-end.html.ini   | 2 +-
 .../css-view-transitions/root-to-shared-animation-incoming.html.ini  | 2 +-
 .../css/css-view-transitions/root-to-shared-animation-start.html.ini | 2 +-
 .../meta/css/css-view-transitions/set-universal-specificity.html.ini | 2 +-
 .../meta/css/css-view-transitions/style-inheritance.html.ini         | 3 +--
 .../synchronous-callback-skipped-before-run.html.ini                 | 3 +--
 .../transition-skipped-after-animation-started.html.ini              | 3 +--
 .../transition-skipped-from-invalid-callback.html.ini                | 3 +--
 .../unset-and-initial-view-transition-name.html.ini                  | 3 +--
 .../view-transition-name-on-removed-element.html.ini                 | 3 +--
 .../meta/css/css-view-transitions/web-animations-api.html.ini        | 2 +-
 .../tests/content-security-policy/inheritance/history.sub.html       | 2 +-
 .../tests/css/css-view-transitions/3d-transform-incoming.html        | 2 ++
 .../tests/css/css-view-transitions/3d-transform-outgoing.html        | 2 ++
 .../css/css-view-transitions/content-smaller-than-box-size.html      | 2 ++
 .../css-view-transitions/content-visibility-auto-shared-element.html | 2 ++
 .../css/css-view-transitions/content-with-clip-max-texture-size.html | 2 ++
 .../tests/css/css-view-transitions/content-with-clip-root.html       | 2 ++
 .../tests/css/css-view-transitions/content-with-clip.html            | 2 ++
 .../tests/css/css-view-transitions/content-with-inline-child.html    | 2 ++
 .../css/css-view-transitions/content-with-transform-new-image.html   | 2 ++
 .../css/css-view-transitions/content-with-transform-old-image.html   | 2 ++
 .../css/css-view-transitions/css-tags-paint-order-with-entry.html    | 2 ++
 .../tests/css/css-view-transitions/css-tags-paint-order.html         | 2 ++
 .../tests/css/css-view-transitions/css-tags-shared-element.html      | 2 ++
 .../dialog-in-top-layer-during-transition-new.html                   | 2 ++
 .../dialog-in-top-layer-during-transition-old.html                   | 2 ++
 .../css/css-view-transitions/duplicate-tag-rejects-capture.html      | 3 ++-
 .../tests/css/css-view-transitions/duplicate-tag-rejects-start.html  | 3 ++-
 .../tests/css/css-view-transitions/element-with-overflow.html        | 2 ++
 .../tests/css/css-view-transitions/event-pseudo-name.html            | 1 +
 .../tests/css/css-view-transitions/far-away-capture.html             | 2 ++
 .../css-view-transitions/hit-test-unpainted-element-from-point.html  | 2 +-
 .../tests/css/css-view-transitions/hit-test-unpainted-element.html   | 2 ++
 .../tests/css/css-view-transitions/hit-test-unrelated-element.html   | 2 ++
 .../tests/css/css-view-transitions/iframe-transition.sub.html        | 2 ++
 .../input-blocked-when-rendering-suppressed.html                     | 3 ++-
 .../web-platform/tests/css/css-view-transitions/japanese-tag.html    | 2 ++
 .../css/css-view-transitions/mix-blend-mode-only-on-transition.html  | 3 ++-
 .../tests/css/css-view-transitions/new-and-old-sizes-match-ref.html  | 2 ++
 .../tests/css/css-view-transitions/new-and-old-sizes-match.html      | 2 ++
 .../css/css-view-transitions/new-content-captures-clip-path.html     | 2 ++
 .../css-view-transitions/new-content-captures-different-size.html    | 2 ++
 .../tests/css/css-view-transitions/new-content-captures-opacity.html | 2 ++
 .../tests/css/css-view-transitions/new-content-captures-root.html    | 2 ++
 .../css-view-transitions/new-content-container-writing-modes.html    | 2 ++
 .../css/css-view-transitions/new-content-element-writing-modes.html  | 2 ++
 .../tests/css/css-view-transitions/new-content-has-scrollbars.html   | 2 ++
 .../css/css-view-transitions/new-content-intrinsic-aspect-ratio.html | 2 ++
 .../tests/css/css-view-transitions/new-content-is-empty-div.html     | 2 ++
 .../tests/css/css-view-transitions/new-content-object-fit-fill.html  | 2 ++
 .../tests/css/css-view-transitions/new-content-object-fit-none.html  | 2 ++
 .../new-content-object-view-box-clip-path-reference.html             | 2 ++
 .../css-view-transitions/new-content-object-view-box-clip-path.html  | 2 ++
 .../new-content-object-view-box-overflow-clipped.html                | 2 ++
 .../css-view-transitions/new-content-object-view-box-overflow.html   | 2 ++
 .../tests/css/css-view-transitions/new-content-scaling.html          | 2 ++
 .../css/css-view-transitions/new-content-with-overflow-zoomed.html   | 2 ++
 .../tests/css/css-view-transitions/new-content-with-overflow.html    | 2 ++
 .../tests/css/css-view-transitions/new-element-on-start.html         | 2 ++
 .../css/css-view-transitions/new-root-vertical-writing-mode.html     | 2 ++
 .../no-containment-on-new-element-mid-transition.html                | 3 ++-
 .../css/css-view-transitions/no-containment-on-new-element.html      | 3 ++-
 .../css/css-view-transitions/no-containment-on-old-element.html      | 3 ++-
 .../tests/css/css-view-transitions/no-crash-set-exception.html       | 3 ++-
 .../css-view-transitions/no-css-animation-while-render-blocked.html  | 3 ++-
 .../tests/css/css-view-transitions/no-raf-while-render-blocked.html  | 3 ++-
 .../web-platform/tests/css/css-view-transitions/no-root-capture.html | 2 ++
 .../tests/css/css-view-transitions/nothing-captured.html             | 2 ++
 .../tests/css/css-view-transitions/object-view-box-new-image.html    | 2 ++
 .../tests/css/css-view-transitions/object-view-box-old-image.html    | 2 ++
 .../css/css-view-transitions/old-content-captures-clip-path.html     | 2 ++
 .../css-view-transitions/old-content-captures-different-size.html    | 2 ++
 .../tests/css/css-view-transitions/old-content-captures-opacity.html | 2 ++
 .../tests/css/css-view-transitions/old-content-captures-root.html    | 2 ++
 .../css-view-transitions/old-content-container-writing-modes.html    | 2 ++
 .../css/css-view-transitions/old-content-element-writing-modes.html  | 2 ++
 .../tests/css/css-view-transitions/old-content-has-scrollbars.html   | 2 ++
 .../css/css-view-transitions/old-content-intrinsic-aspect-ratio.html | 2 ++
 .../tests/css/css-view-transitions/old-content-is-empty-div.html     | 2 ++
 .../tests/css/css-view-transitions/old-content-object-fit-fill.html  | 2 ++
 .../tests/css/css-view-transitions/old-content-object-fit-none.html  | 2 ++
 .../old-content-object-view-box-clip-path-reference.html             | 2 ++
 .../css-view-transitions/old-content-object-view-box-clip-path.html  | 2 ++
 .../css-view-transitions/old-content-object-view-box-overflow.html   | 2 ++
 .../css/css-view-transitions/old-content-with-overflow-zoomed.html   | 2 ++
 .../tests/css/css-view-transitions/old-content-with-overflow.html    | 2 ++
 .../css/css-view-transitions/old-root-vertical-writing-mode.html     | 2 ++
 .../pseudo-computed-style-stays-in-sync-with-new-element.html        | 3 ++-
 .../tests/css/css-view-transitions/pseudo-get-computed-style.html    | 4 +++-
 .../css-view-transitions/ready_resolves_after_dom_before_raf.html    | 3 ++-
 .../css/css-view-transitions/root-captured-as-different-tag.html     | 2 ++
 .../css-view-transitions/root-scrollbar-with-fixed-background.html   | 2 ++
 .../css/css-view-transitions/root-style-change-during-animation.html | 2 ++
 .../tests/css/css-view-transitions/root-to-shared-animation-end.html | 2 ++
 .../css/css-view-transitions/root-to-shared-animation-incoming.html  | 2 ++
 .../css/css-view-transitions/root-to-shared-animation-start.html     | 2 ++
 .../tests/css/css-view-transitions/set-universal-specificity.html    | 2 ++
 .../tests/css/css-view-transitions/style-inheritance.html            | 3 ++-
 .../synchronous-callback-skipped-before-run.html                     | 3 ++-
 .../transition-skipped-after-animation-started.html                  | 3 ++-
 .../transition-skipped-from-invalid-callback.html                    | 3 ++-
 .../css-view-transitions/unset-and-initial-view-transition-name.html | 3 ++-
 .../css-view-transitions/view-transition-name-on-added-element.html  | 3 ++-
 .../view-transition-name-on-removed-element.html                     | 3 ++-
 .../tests/css/css-view-transitions/web-animations-api.html           | 2 ++
 180 files changed, 272 insertions(+), 124 deletions(-)
 delete mode 100644 testing/web-platform/meta/css/css-view-transitions/3d-transform-outgoing.html.ini
 delete mode 100644 testing/web-platform/meta/css/css-view-transitions/new-and-old-sizes-match.html.ini

diff --git a/testing/web-platform/meta/css/css-view-transitions/3d-transform-incoming.html.ini b/testing/web-platform/meta/css/css-view-transitions/3d-transform-incoming.html.ini
index b1c35db923bd..b2c8041faeba 100644
--- a/testing/web-platform/meta/css/css-view-transitions/3d-transform-incoming.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/3d-transform-incoming.html.ini
@@ -1,2 +1,2 @@
 [3d-transform-incoming.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/3d-transform-outgoing.html.ini b/testing/web-platform/meta/css/css-view-transitions/3d-transform-outgoing.html.ini
deleted file mode 100644
index 68653b292464..000000000000
--- a/testing/web-platform/meta/css/css-view-transitions/3d-transform-outgoing.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[3d-transform-outgoing.html]
-  expected: TIMEOUT
diff --git a/testing/web-platform/meta/css/css-view-transitions/content-smaller-than-box-size.html.ini b/testing/web-platform/meta/css/css-view-transitions/content-smaller-than-box-size.html.ini
index 3cce9c885c06..dd6b575d76f0 100644
--- a/testing/web-platform/meta/css/css-view-transitions/content-smaller-than-box-size.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/content-smaller-than-box-size.html.ini
@@ -1,2 +1,2 @@
 [content-smaller-than-box-size.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/content-visibility-auto-shared-element.html.ini b/testing/web-platform/meta/css/css-view-transitions/content-visibility-auto-shared-element.html.ini
index c063e56033ae..17013c52beca 100644
--- a/testing/web-platform/meta/css/css-view-transitions/content-visibility-auto-shared-element.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/content-visibility-auto-shared-element.html.ini
@@ -1,2 +1,2 @@
 [content-visibility-auto-shared-element.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/content-with-clip-max-texture-size.html.ini b/testing/web-platform/meta/css/css-view-transitions/content-with-clip-max-texture-size.html.ini
index b9b87fe87860..9adefd74cdd6 100644
--- a/testing/web-platform/meta/css/css-view-transitions/content-with-clip-max-texture-size.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/content-with-clip-max-texture-size.html.ini
@@ -1,2 +1,2 @@
 [content-with-clip-max-texture-size.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/content-with-clip-root.html.ini b/testing/web-platform/meta/css/css-view-transitions/content-with-clip-root.html.ini
index ac13765e2832..19599dc96cac 100644
--- a/testing/web-platform/meta/css/css-view-transitions/content-with-clip-root.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/content-with-clip-root.html.ini
@@ -1,2 +1,2 @@
 [content-with-clip-root.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/content-with-clip.html.ini b/testing/web-platform/meta/css/css-view-transitions/content-with-clip.html.ini
index 1e716b3051c3..046323dcb0f1 100644
--- a/testing/web-platform/meta/css/css-view-transitions/content-with-clip.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/content-with-clip.html.ini
@@ -1,2 +1,2 @@
 [content-with-clip.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/content-with-inline-child.html.ini b/testing/web-platform/meta/css/css-view-transitions/content-with-inline-child.html.ini
index 675a9b610199..3c9eeb041ddc 100644
--- a/testing/web-platform/meta/css/css-view-transitions/content-with-inline-child.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/content-with-inline-child.html.ini
@@ -1,2 +1,2 @@
 [content-with-inline-child.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/content-with-transform-new-image.html.ini b/testing/web-platform/meta/css/css-view-transitions/content-with-transform-new-image.html.ini
index 7c516e2661a1..8ba8457eec10 100644
--- a/testing/web-platform/meta/css/css-view-transitions/content-with-transform-new-image.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/content-with-transform-new-image.html.ini
@@ -1,2 +1,2 @@
 [content-with-transform-new-image.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/content-with-transform-old-image.html.ini b/testing/web-platform/meta/css/css-view-transitions/content-with-transform-old-image.html.ini
index 9c068e214e65..54b268b2aed3 100644
--- a/testing/web-platform/meta/css/css-view-transitions/content-with-transform-old-image.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/content-with-transform-old-image.html.ini
@@ -1,2 +1,2 @@
 [content-with-transform-old-image.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/css-tags-paint-order-with-entry.html.ini b/testing/web-platform/meta/css/css-view-transitions/css-tags-paint-order-with-entry.html.ini
index f3ca7907662b..2baa468e7762 100644
--- a/testing/web-platform/meta/css/css-view-transitions/css-tags-paint-order-with-entry.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/css-tags-paint-order-with-entry.html.ini
@@ -1,2 +1,2 @@
 [css-tags-paint-order-with-entry.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/css-tags-paint-order.html.ini b/testing/web-platform/meta/css/css-view-transitions/css-tags-paint-order.html.ini
index aff84d82c8cd..0e7c2730e21a 100644
--- a/testing/web-platform/meta/css/css-view-transitions/css-tags-paint-order.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/css-tags-paint-order.html.ini
@@ -1,2 +1,2 @@
 [css-tags-paint-order.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/css-tags-shared-element.html.ini b/testing/web-platform/meta/css/css-view-transitions/css-tags-shared-element.html.ini
index cd9dc58dd5f6..3c6300dd4802 100644
--- a/testing/web-platform/meta/css/css-view-transitions/css-tags-shared-element.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/css-tags-shared-element.html.ini
@@ -1,2 +1,2 @@
 [css-tags-shared-element.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/dialog-in-top-layer-during-transition-new.html.ini b/testing/web-platform/meta/css/css-view-transitions/dialog-in-top-layer-during-transition-new.html.ini
index 9510a5d46f71..17cf0b949be7 100644
--- a/testing/web-platform/meta/css/css-view-transitions/dialog-in-top-layer-during-transition-new.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/dialog-in-top-layer-during-transition-new.html.ini
@@ -1,2 +1,2 @@
 [dialog-in-top-layer-during-transition-new.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/dialog-in-top-layer-during-transition-old.html.ini b/testing/web-platform/meta/css/css-view-transitions/dialog-in-top-layer-during-transition-old.html.ini
index e51762790cd2..3a4d114bbe30 100644
--- a/testing/web-platform/meta/css/css-view-transitions/dialog-in-top-layer-during-transition-old.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/dialog-in-top-layer-during-transition-old.html.ini
@@ -1,2 +1,2 @@
 [dialog-in-top-layer-during-transition-old.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/element-with-overflow.html.ini b/testing/web-platform/meta/css/css-view-transitions/element-with-overflow.html.ini
index c951c41ca3c4..ad317c23ecd8 100644
--- a/testing/web-platform/meta/css/css-view-transitions/element-with-overflow.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/element-with-overflow.html.ini
@@ -1,2 +1,2 @@
 [element-with-overflow.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/far-away-capture.html.ini b/testing/web-platform/meta/css/css-view-transitions/far-away-capture.html.ini
index 571e9ddecea5..01ebbf177c3e 100644
--- a/testing/web-platform/meta/css/css-view-transitions/far-away-capture.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/far-away-capture.html.ini
@@ -1,2 +1,2 @@
 [far-away-capture.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/hit-test-unpainted-element.html.ini b/testing/web-platform/meta/css/css-view-transitions/hit-test-unpainted-element.html.ini
index 2c96cdbf2d74..816eb7f0a792 100644
--- a/testing/web-platform/meta/css/css-view-transitions/hit-test-unpainted-element.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/hit-test-unpainted-element.html.ini
@@ -1,2 +1,2 @@
 [hit-test-unpainted-element.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/hit-test-unrelated-element.html.ini b/testing/web-platform/meta/css/css-view-transitions/hit-test-unrelated-element.html.ini
index 15f482758905..dca27ccae7c3 100644
--- a/testing/web-platform/meta/css/css-view-transitions/hit-test-unrelated-element.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/hit-test-unrelated-element.html.ini
@@ -1,2 +1,2 @@
 [hit-test-unrelated-element.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/iframe-transition.sub.html.ini b/testing/web-platform/meta/css/css-view-transitions/iframe-transition.sub.html.ini
index 84c2d3f7325b..4d2697f9995f 100644
--- a/testing/web-platform/meta/css/css-view-transitions/iframe-transition.sub.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/iframe-transition.sub.html.ini
@@ -1,2 +1,2 @@
 [iframe-transition.sub.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/input-blocked-when-rendering-suppressed.html.ini b/testing/web-platform/meta/css/css-view-transitions/input-blocked-when-rendering-suppressed.html.ini
index c517bf574dd0..7deeaa4a9925 100644
--- a/testing/web-platform/meta/css/css-view-transitions/input-blocked-when-rendering-suppressed.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/input-blocked-when-rendering-suppressed.html.ini
@@ -1,4 +1,3 @@
 [input-blocked-when-rendering-suppressed.html]
-  expected: ERROR
   [Input when rendering suppressed is ignored]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/japanese-tag.html.ini b/testing/web-platform/meta/css/css-view-transitions/japanese-tag.html.ini
index 634fd7c42806..3b8aad5ac4e1 100644
--- a/testing/web-platform/meta/css/css-view-transitions/japanese-tag.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/japanese-tag.html.ini
@@ -1,2 +1,2 @@
 [japanese-tag.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-and-old-sizes-match.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-and-old-sizes-match.html.ini
deleted file mode 100644
index 3e11e97538b1..000000000000
--- a/testing/web-platform/meta/css/css-view-transitions/new-and-old-sizes-match.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[new-and-old-sizes-match.html]
-  expected: TIMEOUT
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-captures-clip-path.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-captures-clip-path.html.ini
index 31611417c3c7..857d28d59b24 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-captures-clip-path.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-captures-clip-path.html.ini
@@ -1,2 +1,2 @@
 [new-content-captures-clip-path.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-captures-different-size.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-captures-different-size.html.ini
index 2a830494ec0d..c9555baddae7 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-captures-different-size.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-captures-different-size.html.ini
@@ -1,2 +1,2 @@
 [new-content-captures-different-size.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-captures-opacity.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-captures-opacity.html.ini
index 2b9ab5c43ee5..bb2bfdd1762c 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-captures-opacity.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-captures-opacity.html.ini
@@ -1,2 +1,2 @@
 [new-content-captures-opacity.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-captures-root.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-captures-root.html.ini
index 13e3cd0ee7ae..c7f61f9fcf34 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-captures-root.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-captures-root.html.ini
@@ -1,2 +1,2 @@
 [new-content-captures-root.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-container-writing-modes.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-container-writing-modes.html.ini
index ace8cd403dc1..c3e6f5457c44 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-container-writing-modes.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-container-writing-modes.html.ini
@@ -1,2 +1,2 @@
 [new-content-container-writing-modes.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-element-writing-modes.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-element-writing-modes.html.ini
index e858be9a063c..83d5122a968b 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-element-writing-modes.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-element-writing-modes.html.ini
@@ -1,2 +1,2 @@
 [new-content-element-writing-modes.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-has-scrollbars.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-has-scrollbars.html.ini
index 077736731570..6452ad9d6076 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-has-scrollbars.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-has-scrollbars.html.ini
@@ -1,2 +1,2 @@
 [new-content-has-scrollbars.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-intrinsic-aspect-ratio.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-intrinsic-aspect-ratio.html.ini
index 9c1267bf8a47..fa18c60023d7 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-intrinsic-aspect-ratio.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-intrinsic-aspect-ratio.html.ini
@@ -1,2 +1,2 @@
 [new-content-intrinsic-aspect-ratio.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-is-empty-div.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-is-empty-div.html.ini
index 0805b5fb3d90..39b37c5ae3ff 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-is-empty-div.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-is-empty-div.html.ini
@@ -1,2 +1,2 @@
 [new-content-is-empty-div.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-object-fit-fill.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-object-fit-fill.html.ini
index 52659a99f5eb..222e6b5c8916 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-object-fit-fill.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-object-fit-fill.html.ini
@@ -1,2 +1,2 @@
 [new-content-object-fit-fill.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-object-fit-none.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-object-fit-none.html.ini
index 6dc0cdb77429..f16f679da4e1 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-object-fit-none.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-object-fit-none.html.ini
@@ -1,2 +1,2 @@
 [new-content-object-fit-none.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-clip-path-reference.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-clip-path-reference.html.ini
index 1984cf88e274..ae0ce744792e 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-clip-path-reference.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-clip-path-reference.html.ini
@@ -1,2 +1,2 @@
 [new-content-object-view-box-clip-path-reference.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-clip-path.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-clip-path.html.ini
index fcbd352cb104..5592e6539db6 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-clip-path.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-clip-path.html.ini
@@ -1,2 +1,2 @@
 [new-content-object-view-box-clip-path.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-overflow-clipped.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-overflow-clipped.html.ini
index 985770712469..ab8549382b28 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-overflow-clipped.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-overflow-clipped.html.ini
@@ -1,2 +1,2 @@
 [new-content-object-view-box-overflow-clipped.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-overflow.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-overflow.html.ini
index aa69eb6b1360..123812233d4d 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-overflow.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-object-view-box-overflow.html.ini
@@ -1,2 +1,2 @@
 [new-content-object-view-box-overflow.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-scaling.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-scaling.html.ini
index 750c7e9cfbec..5793134f2422 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-scaling.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-scaling.html.ini
@@ -1,2 +1,2 @@
 [new-content-scaling.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-with-overflow-zoomed.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-with-overflow-zoomed.html.ini
index c9ece9ecc04e..268e9974922b 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-with-overflow-zoomed.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-with-overflow-zoomed.html.ini
@@ -1,2 +1,2 @@
 [new-content-with-overflow-zoomed.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-content-with-overflow.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-content-with-overflow.html.ini
index 21c88d087918..e5e6fae26026 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-content-with-overflow.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-content-with-overflow.html.ini
@@ -1,2 +1,2 @@
 [new-content-with-overflow.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-element-on-start.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-element-on-start.html.ini
index f8e58c936f4c..852b47a73649 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-element-on-start.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-element-on-start.html.ini
@@ -1,2 +1,2 @@
 [new-element-on-start.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/new-root-vertical-writing-mode.html.ini b/testing/web-platform/meta/css/css-view-transitions/new-root-vertical-writing-mode.html.ini
index b14891cbdf67..2f7cbaf31ae7 100644
--- a/testing/web-platform/meta/css/css-view-transitions/new-root-vertical-writing-mode.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/new-root-vertical-writing-mode.html.ini
@@ -1,2 +1,2 @@
 [new-root-vertical-writing-mode.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/no-containment-on-new-element-mid-transition.html.ini b/testing/web-platform/meta/css/css-view-transitions/no-containment-on-new-element-mid-transition.html.ini
index 64f4b26e8a77..ca7dd2e55f55 100644
--- a/testing/web-platform/meta/css/css-view-transitions/no-containment-on-new-element-mid-transition.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/no-containment-on-new-element-mid-transition.html.ini
@@ -1,4 +1,3 @@
 [no-containment-on-new-element-mid-transition.html]
-  expected: ERROR
   [new element becoming uncontained should skip the transition]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/no-containment-on-new-element.html.ini b/testing/web-platform/meta/css/css-view-transitions/no-containment-on-new-element.html.ini
index 0187830a80a5..68916853bf5b 100644
--- a/testing/web-platform/meta/css/css-view-transitions/no-containment-on-new-element.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/no-containment-on-new-element.html.ini
@@ -1,4 +1,3 @@
 [no-containment-on-new-element.html]
-  expected: ERROR
   [uncontained new element should skip the transition]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/no-containment-on-old-element.html.ini b/testing/web-platform/meta/css/css-view-transitions/no-containment-on-old-element.html.ini
index a94a13c6bd0b..4ac5cb63f6f3 100644
--- a/testing/web-platform/meta/css/css-view-transitions/no-containment-on-old-element.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/no-containment-on-old-element.html.ini
@@ -1,4 +1,3 @@
 [no-containment-on-old-element.html]
-  expected: ERROR
   [uncontained old element should skip the transition]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/no-css-animation-while-render-blocked.html.ini b/testing/web-platform/meta/css/css-view-transitions/no-css-animation-while-render-blocked.html.ini
index ac5664d6d4cc..f9dd1b34ed07 100644
--- a/testing/web-platform/meta/css/css-view-transitions/no-css-animation-while-render-blocked.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/no-css-animation-while-render-blocked.html.ini
@@ -1,4 +1,3 @@
 [no-css-animation-while-render-blocked.html]
-  expected: ERROR
   [CSS animation is blocked until prepare callback]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/no-raf-while-render-blocked.html.ini b/testing/web-platform/meta/css/css-view-transitions/no-raf-while-render-blocked.html.ini
index d652bd433a6b..aa486fbec04c 100644
--- a/testing/web-platform/meta/css/css-view-transitions/no-raf-while-render-blocked.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/no-raf-while-render-blocked.html.ini
@@ -1,4 +1,3 @@
 [no-raf-while-render-blocked.html]
-  expected: ERROR
   [rAF is blocked until prepare callback]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/no-root-capture.html.ini b/testing/web-platform/meta/css/css-view-transitions/no-root-capture.html.ini
index 6ebe0a86b828..17790fab03f9 100644
--- a/testing/web-platform/meta/css/css-view-transitions/no-root-capture.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/no-root-capture.html.ini
@@ -1,2 +1,2 @@
 [no-root-capture.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/nothing-captured.html.ini b/testing/web-platform/meta/css/css-view-transitions/nothing-captured.html.ini
index 08e6ad58d6b3..32b14d18fcbf 100644
--- a/testing/web-platform/meta/css/css-view-transitions/nothing-captured.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/nothing-captured.html.ini
@@ -1,2 +1,2 @@
 [nothing-captured.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/object-view-box-new-image.html.ini b/testing/web-platform/meta/css/css-view-transitions/object-view-box-new-image.html.ini
index 42f3adb43ee9..a944f19c681b 100644
--- a/testing/web-platform/meta/css/css-view-transitions/object-view-box-new-image.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/object-view-box-new-image.html.ini
@@ -1,2 +1,2 @@
 [object-view-box-new-image.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/object-view-box-old-image.html.ini b/testing/web-platform/meta/css/css-view-transitions/object-view-box-old-image.html.ini
index 9d67f9864e92..098e08200fc4 100644
--- a/testing/web-platform/meta/css/css-view-transitions/object-view-box-old-image.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/object-view-box-old-image.html.ini
@@ -1,2 +1,2 @@
 [object-view-box-old-image.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-captures-clip-path.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-captures-clip-path.html.ini
index a81ff13f987f..660a6e5a4e57 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-captures-clip-path.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-captures-clip-path.html.ini
@@ -1,2 +1,2 @@
 [old-content-captures-clip-path.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-captures-different-size.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-captures-different-size.html.ini
index b5072ab7f321..782de8ac9567 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-captures-different-size.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-captures-different-size.html.ini
@@ -1,2 +1,2 @@
 [old-content-captures-different-size.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-captures-opacity.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-captures-opacity.html.ini
index 9f85816784c8..8c707afe7044 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-captures-opacity.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-captures-opacity.html.ini
@@ -1,2 +1,2 @@
 [old-content-captures-opacity.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-captures-root.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-captures-root.html.ini
index a3dcab003b98..1ad03fc8d3bb 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-captures-root.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-captures-root.html.ini
@@ -1,2 +1,2 @@
 [old-content-captures-root.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-container-writing-modes.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-container-writing-modes.html.ini
index c04c996ff2b7..62b0617ee8b4 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-container-writing-modes.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-container-writing-modes.html.ini
@@ -1,2 +1,2 @@
 [old-content-container-writing-modes.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-element-writing-modes.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-element-writing-modes.html.ini
index b4e27b1fd9dd..27febda88ced 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-element-writing-modes.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-element-writing-modes.html.ini
@@ -1,2 +1,2 @@
 [old-content-element-writing-modes.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-has-scrollbars.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-has-scrollbars.html.ini
index 25d950b64888..fb5a3b7fea10 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-has-scrollbars.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-has-scrollbars.html.ini
@@ -1,2 +1,2 @@
 [old-content-has-scrollbars.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-intrinsic-aspect-ratio.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-intrinsic-aspect-ratio.html.ini
index 417cab1d279f..59af5df2881c 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-intrinsic-aspect-ratio.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-intrinsic-aspect-ratio.html.ini
@@ -1,2 +1,2 @@
 [old-content-intrinsic-aspect-ratio.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-is-empty-div.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-is-empty-div.html.ini
index 62e70640660e..5739224dab6d 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-is-empty-div.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-is-empty-div.html.ini
@@ -1,2 +1,2 @@
 [old-content-is-empty-div.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-object-fit-fill.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-object-fit-fill.html.ini
index d0a1e3e2e197..9b409d736cdb 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-object-fit-fill.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-object-fit-fill.html.ini
@@ -1,2 +1,2 @@
 [old-content-object-fit-fill.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-object-fit-none.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-object-fit-none.html.ini
index ba99e88cc1cf..69a6229882fd 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-object-fit-none.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-object-fit-none.html.ini
@@ -1,2 +1,2 @@
 [old-content-object-fit-none.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-clip-path-reference.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-clip-path-reference.html.ini
index c832fdbbe72d..5d2953f23d23 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-clip-path-reference.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-clip-path-reference.html.ini
@@ -1,2 +1,2 @@
 [old-content-object-view-box-clip-path-reference.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-clip-path.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-clip-path.html.ini
index 19f48b67c621..f9e6bff64d2a 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-clip-path.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-clip-path.html.ini
@@ -1,2 +1,2 @@
 [old-content-object-view-box-clip-path.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-overflow.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-overflow.html.ini
index 9eda867c3b36..0f369bb03e2c 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-overflow.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-object-view-box-overflow.html.ini
@@ -1,2 +1,2 @@
 [old-content-object-view-box-overflow.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-with-overflow-zoomed.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-with-overflow-zoomed.html.ini
index 14e266fa5fb3..fd9d6e2b9e56 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-with-overflow-zoomed.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-with-overflow-zoomed.html.ini
@@ -1,2 +1,2 @@
 [old-content-with-overflow-zoomed.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-content-with-overflow.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-content-with-overflow.html.ini
index b6234bc31a73..7381b140cae7 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-content-with-overflow.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-content-with-overflow.html.ini
@@ -1,2 +1,2 @@
 [old-content-with-overflow.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/old-root-vertical-writing-mode.html.ini b/testing/web-platform/meta/css/css-view-transitions/old-root-vertical-writing-mode.html.ini
index b7caf2d1f705..4500fd227965 100644
--- a/testing/web-platform/meta/css/css-view-transitions/old-root-vertical-writing-mode.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/old-root-vertical-writing-mode.html.ini
@@ -1,2 +1,2 @@
 [old-root-vertical-writing-mode.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/pseudo-computed-style-stays-in-sync-with-new-element.html.ini b/testing/web-platform/meta/css/css-view-transitions/pseudo-computed-style-stays-in-sync-with-new-element.html.ini
index a46ced46f9a3..d28519d677e7 100644
--- a/testing/web-platform/meta/css/css-view-transitions/pseudo-computed-style-stays-in-sync-with-new-element.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/pseudo-computed-style-stays-in-sync-with-new-element.html.ini
@@ -1,4 +1,3 @@
 [pseudo-computed-style-stays-in-sync-with-new-element.html]
-  expected: ERROR
   [computed style on pseudo-element stays in sync with the DOM element]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/pseudo-get-computed-style.html.ini b/testing/web-platform/meta/css/css-view-transitions/pseudo-get-computed-style.html.ini
index fc91230544c3..a2886dced835 100644
--- a/testing/web-platform/meta/css/css-view-transitions/pseudo-get-computed-style.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/pseudo-get-computed-style.html.ini
@@ -1,7 +1,6 @@
 [pseudo-get-computed-style.html]
-  expected: ERROR
   [position property of pseudo elements]
-    expected: TIMEOUT
+    expected: FAIL
 
   [position property of pseudo elements with prepare api]
-    expected: NOTRUN
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/root-captured-as-different-tag.html.ini b/testing/web-platform/meta/css/css-view-transitions/root-captured-as-different-tag.html.ini
index 8bef666cf62c..45c9965a043d 100644
--- a/testing/web-platform/meta/css/css-view-transitions/root-captured-as-different-tag.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/root-captured-as-different-tag.html.ini
@@ -1,2 +1,2 @@
 [root-captured-as-different-tag.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/root-scrollbar-with-fixed-background.html.ini b/testing/web-platform/meta/css/css-view-transitions/root-scrollbar-with-fixed-background.html.ini
index 6967b0a00e50..c5477ecf463f 100644
--- a/testing/web-platform/meta/css/css-view-transitions/root-scrollbar-with-fixed-background.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/root-scrollbar-with-fixed-background.html.ini
@@ -1,2 +1,2 @@
 [root-scrollbar-with-fixed-background.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/root-style-change-during-animation.html.ini b/testing/web-platform/meta/css/css-view-transitions/root-style-change-during-animation.html.ini
index 374d7df32c95..4e8a35d76ce8 100644
--- a/testing/web-platform/meta/css/css-view-transitions/root-style-change-during-animation.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/root-style-change-during-animation.html.ini
@@ -1,2 +1,2 @@
 [root-style-change-during-animation.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-end.html.ini b/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-end.html.ini
index 1d6e3bc90b9c..6d4d024b6c14 100644
--- a/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-end.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-end.html.ini
@@ -1,2 +1,2 @@
 [root-to-shared-animation-end.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-incoming.html.ini b/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-incoming.html.ini
index b7ee9d61e183..65ef17cbdbfb 100644
--- a/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-incoming.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-incoming.html.ini
@@ -1,2 +1,2 @@
 [root-to-shared-animation-incoming.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-start.html.ini b/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-start.html.ini
index 6febe257cc5f..79aee8a09899 100644
--- a/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-start.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/root-to-shared-animation-start.html.ini
@@ -1,2 +1,2 @@
 [root-to-shared-animation-start.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/set-universal-specificity.html.ini b/testing/web-platform/meta/css/css-view-transitions/set-universal-specificity.html.ini
index fa049794ec57..29a879342349 100644
--- a/testing/web-platform/meta/css/css-view-transitions/set-universal-specificity.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/set-universal-specificity.html.ini
@@ -1,2 +1,2 @@
 [set-universal-specificity.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/style-inheritance.html.ini b/testing/web-platform/meta/css/css-view-transitions/style-inheritance.html.ini
index 45efbc441381..2d0556260a8a 100644
--- a/testing/web-platform/meta/css/css-view-transitions/style-inheritance.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/style-inheritance.html.ini
@@ -1,4 +1,3 @@
 [style-inheritance.html]
-  expected: ERROR
   [style inheritance of pseudo elements]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/synchronous-callback-skipped-before-run.html.ini b/testing/web-platform/meta/css/css-view-transitions/synchronous-callback-skipped-before-run.html.ini
index 75b6f9bf9727..74dad039e1ea 100644
--- a/testing/web-platform/meta/css/css-view-transitions/synchronous-callback-skipped-before-run.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/synchronous-callback-skipped-before-run.html.ini
@@ -1,4 +1,3 @@
 [synchronous-callback-skipped-before-run.html]
-  expected: ERROR
   [finished promise should be resolved if skipTransition() is invoked before a synchronous domUpdated callback is dispatched]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/transition-skipped-after-animation-started.html.ini b/testing/web-platform/meta/css/css-view-transitions/transition-skipped-after-animation-started.html.ini
index f2309922982a..1fd386372fc1 100644
--- a/testing/web-platform/meta/css/css-view-transitions/transition-skipped-after-animation-started.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/transition-skipped-after-animation-started.html.ini
@@ -1,4 +1,3 @@
 [transition-skipped-after-animation-started.html]
-  expected: ERROR
   [skipTransition() after animations have started running should resolve finished promise]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/transition-skipped-from-invalid-callback.html.ini b/testing/web-platform/meta/css/css-view-transitions/transition-skipped-from-invalid-callback.html.ini
index 5bfb19691910..19b8e4e0d791 100644
--- a/testing/web-platform/meta/css/css-view-transitions/transition-skipped-from-invalid-callback.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/transition-skipped-from-invalid-callback.html.ini
@@ -1,4 +1,3 @@
 [transition-skipped-from-invalid-callback.html]
-  expected: ERROR
   [transition skipped because callback has invalid syntax]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/unset-and-initial-view-transition-name.html.ini b/testing/web-platform/meta/css/css-view-transitions/unset-and-initial-view-transition-name.html.ini
index a68a5a33d977..47d69a5cb064 100644
--- a/testing/web-platform/meta/css/css-view-transitions/unset-and-initial-view-transition-name.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/unset-and-initial-view-transition-name.html.ini
@@ -1,4 +1,3 @@
 [unset-and-initial-view-transition-name.html]
-  expected: ERROR
   [validates that view-transition-name: unset or initial are ignored]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/view-transition-name-on-removed-element.html.ini b/testing/web-platform/meta/css/css-view-transitions/view-transition-name-on-removed-element.html.ini
index 4f5be90788f8..1e5f7f997791 100644
--- a/testing/web-platform/meta/css/css-view-transitions/view-transition-name-on-removed-element.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/view-transition-name-on-removed-element.html.ini
@@ -1,4 +1,3 @@
 [view-transition-name-on-removed-element.html]
-  expected: ERROR
   [view-transition-name on an element removed by script should not be visited when discovering named elements]
-    expected: TIMEOUT
+    expected: FAIL
diff --git a/testing/web-platform/meta/css/css-view-transitions/web-animations-api.html.ini b/testing/web-platform/meta/css/css-view-transitions/web-animations-api.html.ini
index 038359f61f37..48b3c25ccd08 100644
--- a/testing/web-platform/meta/css/css-view-transitions/web-animations-api.html.ini
+++ b/testing/web-platform/meta/css/css-view-transitions/web-animations-api.html.ini
@@ -1,2 +1,2 @@
 [web-animations-api.html]
-  expected: TIMEOUT
+  expected: FAIL
diff --git a/testing/web-platform/tests/content-security-policy/inheritance/history.sub.html b/testing/web-platform/tests/content-security-policy/inheritance/history.sub.html
index 6ebd679a2807..5ea6abe8fb33 100644
--- a/testing/web-platform/tests/content-security-policy/inheritance/history.sub.html
+++ b/testing/web-platform/tests/content-security-policy/inheritance/history.sub.html
@@ -133,7 +133,7 @@
 
       // Closing fails sometimes on Firefox:
       // https://bugzilla.mozilla.org/show_bug.cgi?id=1698093
-      t.add_cleanup(() => { try { popup.close(); } catch {} });
+      t.add_cleanup(() => { popup.close(); });
 
       // Perform a real navigation in the popup. This is needed because the
       // initial empty document is not stored in history (so there is no way of
diff --git a/testing/web-platform/tests/css/css-view-transitions/3d-transform-incoming.html b/testing/web-platform/tests/css/css-view-transitions/3d-transform-incoming.html
index 1c3a20debbcb..d852108ffa48 100644
--- a/testing/web-platform/tests/css/css-view-transitions/3d-transform-incoming.html
+++ b/testing/web-platform/tests/css/css-view-transitions/3d-transform-incoming.html
@@ -50,6 +50,8 @@ div { box-sizing: border-box; will-change: transform }
 <div id=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 function runTest() {
   document.startViewTransition(() => {
     wrapper.classList.toggle("wrap_perspective");
diff --git a/testing/web-platform/tests/css/css-view-transitions/3d-transform-outgoing.html b/testing/web-platform/tests/css/css-view-transitions/3d-transform-outgoing.html
index 2a2319830afd..3cb29527c40d 100644
--- a/testing/web-platform/tests/css/css-view-transitions/3d-transform-outgoing.html
+++ b/testing/web-platform/tests/css/css-view-transitions/3d-transform-outgoing.html
@@ -51,6 +51,8 @@ div { box-sizing: border-box; will-change: transform }
 <div id=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 function runTest() {
   document.startViewTransition(() => {
     wrapper.classList.toggle("wrap_perspective");
diff --git a/testing/web-platform/tests/css/css-view-transitions/content-smaller-than-box-size.html b/testing/web-platform/tests/css/css-view-transitions/content-smaller-than-box-size.html
index f87a18cc4c34..8cd5bc412dcb 100644
--- a/testing/web-platform/tests/css/css-view-transitions/content-smaller-than-box-size.html
+++ b/testing/web-platform/tests/css/css-view-transitions/content-smaller-than-box-size.html
@@ -43,6 +43,8 @@ html::view-transition-old(target) { animation: unset; opacity: 1; }
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(takeScreenshot);
diff --git a/testing/web-platform/tests/css/css-view-transitions/content-visibility-auto-shared-element.html b/testing/web-platform/tests/css/css-view-transitions/content-visibility-auto-shared-element.html
index 9825dfa958a1..b678f485f69f 100644
--- a/testing/web-platform/tests/css/css-view-transitions/content-visibility-auto-shared-element.html
+++ b/testing/web-platform/tests/css/css-view-transitions/content-visibility-auto-shared-element.html
@@ -65,6 +65,8 @@ html::view-transition { background: pink }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   lockme.classList.add("locked");
   document.startViewTransition(() => {
diff --git a/testing/web-platform/tests/css/css-view-transitions/content-with-clip-max-texture-size.html b/testing/web-platform/tests/css/css-view-transitions/content-with-clip-max-texture-size.html
index dd71e7cb1969..b1c96382810f 100644
--- a/testing/web-platform/tests/css/css-view-transitions/content-with-clip-max-texture-size.html
+++ b/testing/web-platform/tests/css/css-view-transitions/content-with-clip-max-texture-size.html
@@ -54,6 +54,8 @@ html::view-transition-new(target1) { animation: unset; opacity: 1; }
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   scrollblue.scrollIntoView();
 
diff --git a/testing/web-platform/tests/css/css-view-transitions/content-with-clip-root.html b/testing/web-platform/tests/css/css-view-transitions/content-with-clip-root.html
index c014a8c3e2e8..805610bb0788 100644
--- a/testing/web-platform/tests/css/css-view-transitions/content-with-clip-root.html
+++ b/testing/web-platform/tests/css/css-view-transitions/content-with-clip-root.html
@@ -61,6 +61,8 @@ html::view-transition-new(root) { animation: unset; opacity: 1; height: 100%; }
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     // Add a shared element to ensure its bounds don't expand the root snapshot
diff --git a/testing/web-platform/tests/css/css-view-transitions/content-with-clip.html b/testing/web-platform/tests/css/css-view-transitions/content-with-clip.html
index d84b614256b6..7354125b303d 100644
--- a/testing/web-platform/tests/css/css-view-transitions/content-with-clip.html
+++ b/testing/web-platform/tests/css/css-view-transitions/content-with-clip.html
@@ -57,6 +57,8 @@ html::view-transition-new(target2) { animation: unset; opacity: 1; }
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     target1.style = "";
diff --git a/testing/web-platform/tests/css/css-view-transitions/content-with-inline-child.html b/testing/web-platform/tests/css/css-view-transitions/content-with-inline-child.html
index e195f5ff8618..6bae020b8d9f 100644
--- a/testing/web-platform/tests/css/css-view-transitions/content-with-inline-child.html
+++ b/testing/web-platform/tests/css/css-view-transitions/content-with-inline-child.html
@@ -53,6 +53,8 @@ html::view-transition-new(target) { animation: unset; opacity: 0; }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     // Remove the target to ensure the ref is compared against the snapshot.
diff --git a/testing/web-platform/tests/css/css-view-transitions/content-with-transform-new-image.html b/testing/web-platform/tests/css/css-view-transitions/content-with-transform-new-image.html
index 31cd1882b6f1..f459742cd0ba 100644
--- a/testing/web-platform/tests/css/css-view-transitions/content-with-transform-new-image.html
+++ b/testing/web-platform/tests/css/css-view-transitions/content-with-transform-new-image.html
@@ -47,6 +47,8 @@ html::view-transition-old(target) { animation: unset; opacity: 0; }
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   let t = document.startViewTransition(() => {
     requestAnimationFrame(() =>  requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/content-with-transform-old-image.html b/testing/web-platform/tests/css/css-view-transitions/content-with-transform-old-image.html
index 445e1b80b276..a31a2745a676 100644
--- a/testing/web-platform/tests/css/css-view-transitions/content-with-transform-old-image.html
+++ b/testing/web-platform/tests/css/css-view-transitions/content-with-transform-old-image.html
@@ -48,6 +48,8 @@ html::view-transition-new(target) { animation: unset; opacity: 0; }
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() =>  requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/css-tags-paint-order-with-entry.html b/testing/web-platform/tests/css/css-view-transitions/css-tags-paint-order-with-entry.html
index 28a0d6b01a70..9f79ba25e080 100644
--- a/testing/web-platform/tests/css/css-view-transitions/css-tags-paint-order-with-entry.html
+++ b/testing/web-platform/tests/css/css-view-transitions/css-tags-paint-order-with-entry.html
@@ -95,6 +95,8 @@ html::view-transition { background: lightpink; }
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     const f = document.createElement("div");
diff --git a/testing/web-platform/tests/css/css-view-transitions/css-tags-paint-order.html b/testing/web-platform/tests/css/css-view-transitions/css-tags-paint-order.html
index 49c932337aa2..2f71a701ee9a 100644
--- a/testing/web-platform/tests/css/css-view-transitions/css-tags-paint-order.html
+++ b/testing/web-platform/tests/css/css-view-transitions/css-tags-paint-order.html
@@ -81,6 +81,8 @@ html::view-transition { background: lightpink; }
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/css-tags-shared-element.html b/testing/web-platform/tests/css/css-view-transitions/css-tags-shared-element.html
index b750a6b05a4d..fad0d3763de1 100644
--- a/testing/web-platform/tests/css/css-view-transitions/css-tags-shared-element.html
+++ b/testing/web-platform/tests/css/css-view-transitions/css-tags-shared-element.html
@@ -61,6 +61,8 @@ html::view-transition { background: lightpink; }
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     left.classList.remove("left-tag");
diff --git a/testing/web-platform/tests/css/css-view-transitions/dialog-in-top-layer-during-transition-new.html b/testing/web-platform/tests/css/css-view-transitions/dialog-in-top-layer-during-transition-new.html
index d5135be3d0f5..e84167a24892 100644
--- a/testing/web-platform/tests/css/css-view-transitions/dialog-in-top-layer-during-transition-new.html
+++ b/testing/web-platform/tests/css/css-view-transitions/dialog-in-top-layer-during-transition-new.html
@@ -56,6 +56,8 @@ html::view-transition-new(backdrop), html::view-transition-new(dialog) {
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   const transition = document.startViewTransition(() => {
     target.showModal();
diff --git a/testing/web-platform/tests/css/css-view-transitions/dialog-in-top-layer-during-transition-old.html b/testing/web-platform/tests/css/css-view-transitions/dialog-in-top-layer-during-transition-old.html
index da4bcf13afff..672295cd3bd7 100644
--- a/testing/web-platform/tests/css/css-view-transitions/dialog-in-top-layer-during-transition-old.html
+++ b/testing/web-platform/tests/css/css-view-transitions/dialog-in-top-layer-during-transition-old.html
@@ -56,6 +56,8 @@ html::view-transition-old(backdrop), html::view-transition-old(dialog) {
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   target.showModal();
   const transition = document.startViewTransition(() => {
diff --git a/testing/web-platform/tests/css/css-view-transitions/duplicate-tag-rejects-capture.html b/testing/web-platform/tests/css/css-view-transitions/duplicate-tag-rejects-capture.html
index 517502b67418..da340deccb3c 100644
--- a/testing/web-platform/tests/css/css-view-transitions/duplicate-tag-rejects-capture.html
+++ b/testing/web-platform/tests/css/css-view-transitions/duplicate-tag-rejects-capture.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: duplicate tags in the old DOM skip the transition</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -21,6 +21,7 @@ div {
 
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise((resolve, reject) => {
     first.style = "view-transition-name: target";
     second.style = "view-transition-name: target";
diff --git a/testing/web-platform/tests/css/css-view-transitions/duplicate-tag-rejects-start.html b/testing/web-platform/tests/css/css-view-transitions/duplicate-tag-rejects-start.html
index 2d99717df446..f34c337e0c98 100644
--- a/testing/web-platform/tests/css/css-view-transitions/duplicate-tag-rejects-start.html
+++ b/testing/web-platform/tests/css/css-view-transitions/duplicate-tag-rejects-start.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: duplicate tags in the new DOM skip the transition</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -21,6 +21,7 @@ div {
 
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise((resolve, reject) => {
     first.style = "view-transition-name: target";
     let transition = document.startViewTransition(() => {
diff --git a/testing/web-platform/tests/css/css-view-transitions/element-with-overflow.html b/testing/web-platform/tests/css/css-view-transitions/element-with-overflow.html
index 188e00d30967..b600bcec27e6 100644
--- a/testing/web-platform/tests/css/css-view-transitions/element-with-overflow.html
+++ b/testing/web-platform/tests/css/css-view-transitions/element-with-overflow.html
@@ -56,6 +56,8 @@
 <div class="hidden"></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     document.getElementsByClassName("target")[0].style.background="lightgreen";
diff --git a/testing/web-platform/tests/css/css-view-transitions/event-pseudo-name.html b/testing/web-platform/tests/css/css-view-transitions/event-pseudo-name.html
index b6af305c2638..b49cde320896 100644
--- a/testing/web-platform/tests/css/css-view-transitions/event-pseudo-name.html
+++ b/testing/web-platform/tests/css/css-view-transitions/event-pseudo-name.html
@@ -35,6 +35,7 @@ html::view-transition-image-pair(*) {
 <div id=first></div>
 <script>
 async_test(t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   let names = [];
   document.documentElement.addEventListener("animationstart", (e) => {
     names.push(e.pseudoElement);
diff --git a/testing/web-platform/tests/css/css-view-transitions/far-away-capture.html b/testing/web-platform/tests/css/css-view-transitions/far-away-capture.html
index 75e3bdf7515e..f95ec96c7896 100644
--- a/testing/web-platform/tests/css/css-view-transitions/far-away-capture.html
+++ b/testing/web-platform/tests/css/css-view-transitions/far-away-capture.html
@@ -66,6 +66,8 @@ html::view-transition { background: pink }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     content.remove();
diff --git a/testing/web-platform/tests/css/css-view-transitions/hit-test-unpainted-element-from-point.html b/testing/web-platform/tests/css/css-view-transitions/hit-test-unpainted-element-from-point.html
index 390a3669e15a..ec5e40726050 100644
--- a/testing/web-platform/tests/css/css-view-transitions/hit-test-unpainted-element-from-point.html
+++ b/testing/web-platform/tests/css/css-view-transitions/hit-test-unpainted-element-from-point.html
@@ -52,6 +52,7 @@ html::view-transition-new(shared) {
 
 <script>
 async_test(t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   document.startViewTransition(() => {
     target.classList.toggle("before");
     target.classList.toggle("after");
@@ -68,5 +69,4 @@ async_test(t => {
     });
   });
 }, "hit test should not hit unpainted element, but does hit pseudo and unrelated elements");
-
 </script>
diff --git a/testing/web-platform/tests/css/css-view-transitions/hit-test-unpainted-element.html b/testing/web-platform/tests/css/css-view-transitions/hit-test-unpainted-element.html
index 792ddc1a5d97..ef4bc6613a4a 100644
--- a/testing/web-platform/tests/css/css-view-transitions/hit-test-unpainted-element.html
+++ b/testing/web-platform/tests/css/css-view-transitions/hit-test-unpainted-element.html
@@ -46,6 +46,8 @@ html::view-transition-new(shared) {
 <div id=target class=before></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 function mouseMoveToTarget(x, y) {
   return new test_driver.Actions().pointerMove(x, y).send();
 }
diff --git a/testing/web-platform/tests/css/css-view-transitions/hit-test-unrelated-element.html b/testing/web-platform/tests/css/css-view-transitions/hit-test-unrelated-element.html
index 3620e5ea5514..188521d5886e 100644
--- a/testing/web-platform/tests/css/css-view-transitions/hit-test-unrelated-element.html
+++ b/testing/web-platform/tests/css/css-view-transitions/hit-test-unrelated-element.html
@@ -53,6 +53,8 @@ html::view-transition-new(shared) {
 <div id=unrelated></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 function mouseMoveToTarget(x, y) {
   return new test_driver.Actions().pointerMove(x, y).send();
 }
diff --git a/testing/web-platform/tests/css/css-view-transitions/iframe-transition.sub.html b/testing/web-platform/tests/css/css-view-transitions/iframe-transition.sub.html
index 9c64f9768ee5..914db87a9e81 100644
--- a/testing/web-platform/tests/css/css-view-transitions/iframe-transition.sub.html
+++ b/testing/web-platform/tests/css/css-view-transitions/iframe-transition.sub.html
@@ -13,6 +13,8 @@ iframe { width: 500px; height: 500px }
 </style>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 addEventListener("message", takeScreenshot);
 </script>
 
diff --git a/testing/web-platform/tests/css/css-view-transitions/input-blocked-when-rendering-suppressed.html b/testing/web-platform/tests/css/css-view-transitions/input-blocked-when-rendering-suppressed.html
index a571b2342fbc..7f550c86550e 100644
--- a/testing/web-platform/tests/css/css-view-transitions/input-blocked-when-rendering-suppressed.html
+++ b/testing/web-platform/tests/css/css-view-transitions/input-blocked-when-rendering-suppressed.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>Shared transitions: ensure input is discarded when rendering is suppressed</title>
 <link rel="help" href="https://github.com/WICG/view-transitions">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -58,6 +58,7 @@ async function runTest(resolve, reject) {
 }
 
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     // Dispatch an event before starting the test to finish init logic in
     // synthetic input dispatch.
diff --git a/testing/web-platform/tests/css/css-view-transitions/japanese-tag.html b/testing/web-platform/tests/css/css-view-transitions/japanese-tag.html
index d9ad8c579746..6d04155813ef 100644
--- a/testing/web-platform/tests/css/css-view-transitions/japanese-tag.html
+++ b/testing/web-platform/tests/css/css-view-transitions/japanese-tag.html
@@ -73,6 +73,8 @@ html::view-transition { background: lightpink; }
 <div id=three class="shared rl">T</div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     one.remove();
diff --git a/testing/web-platform/tests/css/css-view-transitions/mix-blend-mode-only-on-transition.html b/testing/web-platform/tests/css/css-view-transitions/mix-blend-mode-only-on-transition.html
index a9b9cb7afd3a..5047a067cb7d 100644
--- a/testing/web-platform/tests/css/css-view-transitions/mix-blend-mode-only-on-transition.html
+++ b/testing/web-platform/tests/css/css-view-transitions/mix-blend-mode-only-on-transition.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>SET: Blend modes are set up only in paired transitions</title>
 <link rel="help" href="https://github.com/WICG/view-transitions">
 <link rel="author" href="mailto:vmpstr@chromium.org">
@@ -25,6 +25,7 @@ div {
 
 <script>
 async_test(t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   let transition = document.startViewTransition(() => {
     first.classList.toggle("tagone");
     second.classList.toggle("tagtwo");
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-and-old-sizes-match-ref.html b/testing/web-platform/tests/css/css-view-transitions/new-and-old-sizes-match-ref.html
index 5a645bc788c7..a2f8942fcc36 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-and-old-sizes-match-ref.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-and-old-sizes-match-ref.html
@@ -36,6 +36,8 @@ html::view-transition { background: lightpink; }
 </style>
 <div id=target class=box><div class=inner_overflow>X</div></div>
 <script>
+failIfNot(document.startViewTransition, "Reference missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-and-old-sizes-match.html b/testing/web-platform/tests/css/css-view-transitions/new-and-old-sizes-match.html
index 9eeb8364ab05..b80f90fd7050 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-and-old-sizes-match.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-and-old-sizes-match.html
@@ -38,6 +38,8 @@ html::view-transition { background: lightpink; }
 </style>
 <div id=target class=box><div class=inner_overflow>X</div></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   let t = document.startViewTransition(() => {
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-captures-clip-path.html b/testing/web-platform/tests/css/css-view-transitions/new-content-captures-clip-path.html
index 0e78e0f0ef07..85f29bad1ce8 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-captures-clip-path.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-captures-clip-path.html
@@ -35,6 +35,8 @@ html::view-transition { background: lightpink; }
 </style>
 <div id=e1 class=box></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   let t = document.startViewTransition(() => {
     e1.classList.add("dst");
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-captures-different-size.html b/testing/web-platform/tests/css/css-view-transitions/new-content-captures-different-size.html
index 1cd57f99400c..da9983fc4629 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-captures-different-size.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-captures-different-size.html
@@ -49,6 +49,8 @@ html::view-transition { background: lightpink; }
 <div id=e2 class=box>two</div>
 <div id=e3 class=box>three</div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   let t = document.startViewTransition(() => {
     e1.classList.add("dst");
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-captures-opacity.html b/testing/web-platform/tests/css/css-view-transitions/new-content-captures-opacity.html
index 15ac0b6b99f4..02c43d724b84 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-captures-opacity.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-captures-opacity.html
@@ -32,6 +32,8 @@ html::view-transition { background: lightpink; }
 <div id=e2 class=box></div>
 <div id=e3 class=box></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   let t = document.startViewTransition(() => {
     e1.classList.add("dst");
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-captures-root.html b/testing/web-platform/tests/css/css-view-transitions/new-content-captures-root.html
index d2944ef2a911..3b3fe71cebe1 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-captures-root.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-captures-root.html
@@ -38,6 +38,8 @@ html::view-transition-new(root) { animation-duration: 0s; opacity: 1 }
 <div id=e1 class=box></div>
 <div id=shared></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   let t = document.startViewTransition(() => {
     e1.classList.add("dst");
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-container-writing-modes.html b/testing/web-platform/tests/css/css-view-transitions/new-content-container-writing-modes.html
index 51847e57acc2..75149ca57d3a 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-container-writing-modes.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-container-writing-modes.html
@@ -66,6 +66,8 @@ html::view-transition { background: lightpink; }
 <div class=rl><div id=three class=shared>T</div></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   s1.style = "view-transition-name: s1";
   s2.style = "view-transition-name: s2";
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-element-writing-modes.html b/testing/web-platform/tests/css/css-view-transitions/new-content-element-writing-modes.html
index 0c50e22fc0de..20d81a67db7b 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-element-writing-modes.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-element-writing-modes.html
@@ -70,6 +70,8 @@ html::view-transition { background: lightpink; }
 <div id=three class="rl shared">T</div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   s1.style = "view-transition-name: s1";
   s2.style = "view-transition-name: s2";
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-has-scrollbars.html b/testing/web-platform/tests/css/css-view-transitions/new-content-has-scrollbars.html
index 6f4066a23037..c21eb0e37965 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-has-scrollbars.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-has-scrollbars.html
@@ -46,6 +46,8 @@
 
 <div></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 // Ensure a root snapshot captured in the absence of scrollbars is displayed at
 // full size when rendered in the incoming viewport which is inset by
 // scrollbars. The content must not be scaled-to-fit.
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-intrinsic-aspect-ratio.html b/testing/web-platform/tests/css/css-view-transitions/new-content-intrinsic-aspect-ratio.html
index 88eeddcc80b1..924630f574f4 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-intrinsic-aspect-ratio.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-intrinsic-aspect-ratio.html
@@ -55,6 +55,8 @@ html::view-transition { background: lightpink; }
 <div id=target2 class=box></div>
 <div id=hidden></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-is-empty-div.html b/testing/web-platform/tests/css/css-view-transitions/new-content-is-empty-div.html
index 576c96181bac..420dff2ec31e 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-is-empty-div.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-is-empty-div.html
@@ -45,6 +45,8 @@ html::view-transition { background: lightpink; }
 <div id=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   source.style = "view-transition-name: shared";
   document.startViewTransition(() => {
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-object-fit-fill.html b/testing/web-platform/tests/css/css-view-transitions/new-content-object-fit-fill.html
index 5b1941aa3e6f..04b404de26ef 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-object-fit-fill.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-object-fit-fill.html
@@ -65,6 +65,8 @@ html::view-transition { background: lightpink; }
 <div id=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-object-fit-none.html b/testing/web-platform/tests/css/css-view-transitions/new-content-object-fit-none.html
index d3e4d2dc3def..eab7a0e2070f 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-object-fit-none.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-object-fit-none.html
@@ -58,6 +58,8 @@ html::view-transition { background: lightpink; }
 <div id=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-clip-path-reference.html b/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-clip-path-reference.html
index 6e28a130c86c..8dd5774ec4e7 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-clip-path-reference.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-clip-path-reference.html
@@ -82,6 +82,8 @@ html::view-transition { background: lightpink; }
 </svg>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-clip-path.html b/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-clip-path.html
index 0a56ae220dd3..e1b6c92d2a47 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-clip-path.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-clip-path.html
@@ -71,6 +71,8 @@ html::view-transition { background: lightpink; }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-overflow-clipped.html b/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-overflow-clipped.html
index 7f10f4105d1f..f856a8943336 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-overflow-clipped.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-overflow-clipped.html
@@ -56,6 +56,8 @@ html::view-transition { background: lightpink; }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-overflow.html b/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-overflow.html
index 8031c5b7afda..08a12c23e553 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-overflow.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-object-view-box-overflow.html
@@ -56,6 +56,8 @@ html::view-transition { background: lightpink; }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-scaling.html b/testing/web-platform/tests/css/css-view-transitions/new-content-scaling.html
index 480479ba1f2d..9fc70e39afd4 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-scaling.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-scaling.html
@@ -49,6 +49,8 @@ html::view-transition { background: lightpink; }
 <div id=target class="shared src"><div class=inner></div></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   let t = document.startViewTransition(() => {
     target.classList.remove("src");
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-with-overflow-zoomed.html b/testing/web-platform/tests/css/css-view-transitions/new-content-with-overflow-zoomed.html
index a7a212318ecb..1919daafa287 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-with-overflow-zoomed.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-with-overflow-zoomed.html
@@ -45,6 +45,8 @@ html::view-transition { background: lightpink; }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-content-with-overflow.html b/testing/web-platform/tests/css/css-view-transitions/new-content-with-overflow.html
index 093267f62c2f..2dc0185f7088 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-content-with-overflow.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-content-with-overflow.html
@@ -40,6 +40,8 @@ html::view-transition { background: lightpink; }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-element-on-start.html b/testing/web-platform/tests/css/css-view-transitions/new-element-on-start.html
index 52a7fc920ead..7cd307d58709 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-element-on-start.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-element-on-start.html
@@ -52,6 +52,8 @@ html::view-transition { background: lightpink; }
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   hidden.style.viewTransitionName = "hidden";
   before.style.viewTransitionName = "before";
diff --git a/testing/web-platform/tests/css/css-view-transitions/new-root-vertical-writing-mode.html b/testing/web-platform/tests/css/css-view-transitions/new-root-vertical-writing-mode.html
index 393d05220cf7..fc7d7de277ec 100644
--- a/testing/web-platform/tests/css/css-view-transitions/new-root-vertical-writing-mode.html
+++ b/testing/web-platform/tests/css/css-view-transitions/new-root-vertical-writing-mode.html
@@ -56,6 +56,8 @@ html::view-transition-old(root) { animation: unset; opacity: 0; }
 <div id=two class=shared></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     target.remove();
diff --git a/testing/web-platform/tests/css/css-view-transitions/no-containment-on-new-element-mid-transition.html b/testing/web-platform/tests/css/css-view-transitions/no-containment-on-new-element-mid-transition.html
index 869fd24f42c3..551d2c41f789 100644
--- a/testing/web-platform/tests/css/css-view-transitions/no-containment-on-new-element-mid-transition.html
+++ b/testing/web-platform/tests/css/css-view-transitions/no-containment-on-new-element-mid-transition.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: transition skipped if no containment on new element after animation started</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -25,6 +25,7 @@ html::view-transition-group(target) {
 
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     let transition = document.startViewTransition();
     await transition.domUpdated;
diff --git a/testing/web-platform/tests/css/css-view-transitions/no-containment-on-new-element.html b/testing/web-platform/tests/css/css-view-transitions/no-containment-on-new-element.html
index ecb05373b3e6..46f576dbd564 100644
--- a/testing/web-platform/tests/css/css-view-transitions/no-containment-on-new-element.html
+++ b/testing/web-platform/tests/css/css-view-transitions/no-containment-on-new-element.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: transition skipped if no containment on new element</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -21,6 +21,7 @@ div {
 
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     let transition = document.startViewTransition(() => {
       first.style.contain = "none";
diff --git a/testing/web-platform/tests/css/css-view-transitions/no-containment-on-old-element.html b/testing/web-platform/tests/css/css-view-transitions/no-containment-on-old-element.html
index 22cad098c76c..8b21916019e1 100644
--- a/testing/web-platform/tests/css/css-view-transitions/no-containment-on-old-element.html
+++ b/testing/web-platform/tests/css/css-view-transitions/no-containment-on-old-element.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: transition skipped if no containment on old element</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -20,6 +20,7 @@ div {
 
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     let transition = document.startViewTransition(() => {
       first.style.contain = "paint";
diff --git a/testing/web-platform/tests/css/css-view-transitions/no-crash-set-exception.html b/testing/web-platform/tests/css/css-view-transitions/no-crash-set-exception.html
index 035d050e4487..cb8942d11229 100644
--- a/testing/web-platform/tests/css/css-view-transitions/no-crash-set-exception.html
+++ b/testing/web-platform/tests/css/css-view-transitions/no-crash-set-exception.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>Shared transitions: author styles ignored during prepare</title>
 <link rel="help" href="https://github.com/WICG/view-transitions">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -33,6 +33,7 @@ function validate_background(pseudoString) {
 }
 
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise((resolve, reject) => {
     document.startViewTransition(() => {
       resolve();
diff --git a/testing/web-platform/tests/css/css-view-transitions/no-css-animation-while-render-blocked.html b/testing/web-platform/tests/css/css-view-transitions/no-css-animation-while-render-blocked.html
index 6ed9863a0024..4bc124ce660b 100644
--- a/testing/web-platform/tests/css/css-view-transitions/no-css-animation-while-render-blocked.html
+++ b/testing/web-platform/tests/css/css-view-transitions/no-css-animation-while-render-blocked.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <meta name="timeout" content="long">
-<html class=reftest-wait>
+<html>
 <title>Shared transitions: CSS Animations are paused while render-blocked</title>
 <link rel="help" href="https://github.com/WICG/view-transitions">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -34,6 +34,7 @@ div {
 let renderBlocked = true;
 
 promise_test(() => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     requestAnimationFrame(() => {
       document.startViewTransition(() => {
diff --git a/testing/web-platform/tests/css/css-view-transitions/no-raf-while-render-blocked.html b/testing/web-platform/tests/css/css-view-transitions/no-raf-while-render-blocked.html
index ff2d0589f1a6..566d6f7e3ec9 100644
--- a/testing/web-platform/tests/css/css-view-transitions/no-raf-while-render-blocked.html
+++ b/testing/web-platform/tests/css/css-view-transitions/no-raf-while-render-blocked.html
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <meta name="timeout" content="long">
-<html class=reftest-wait>
+<html>
 <title>Shared transitions: rAF is not issued while render-blocked</title>
 <link rel="help" href="https://github.com/WICG/view-transitions">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -24,6 +24,7 @@ div {
 let renderBlocked = true;
 
 promise_test(() => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     requestAnimationFrame(() => {
       document.startViewTransition(() => {
diff --git a/testing/web-platform/tests/css/css-view-transitions/no-root-capture.html b/testing/web-platform/tests/css/css-view-transitions/no-root-capture.html
index 01033ce00afd..7856a332970e 100644
--- a/testing/web-platform/tests/css/css-view-transitions/no-root-capture.html
+++ b/testing/web-platform/tests/css/css-view-transitions/no-root-capture.html
@@ -43,6 +43,8 @@ This text should appear unmodified, since the root isn't captured.
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/nothing-captured.html b/testing/web-platform/tests/css/css-view-transitions/nothing-captured.html
index acb818e5f87b..c6d45cec8fbd 100644
--- a/testing/web-platform/tests/css/css-view-transitions/nothing-captured.html
+++ b/testing/web-platform/tests/css/css-view-transitions/nothing-captured.html
@@ -36,6 +36,8 @@ This text should appear unmodified, since the root isn't captured.
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/object-view-box-new-image.html b/testing/web-platform/tests/css/css-view-transitions/object-view-box-new-image.html
index 415f18d05316..c23e65f617a7 100644
--- a/testing/web-platform/tests/css/css-view-transitions/object-view-box-new-image.html
+++ b/testing/web-platform/tests/css/css-view-transitions/object-view-box-new-image.html
@@ -58,6 +58,8 @@ html::view-transition-new(target) {
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() =>  requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/object-view-box-old-image.html b/testing/web-platform/tests/css/css-view-transitions/object-view-box-old-image.html
index 2423ff3fd5fd..9e4e4b83fb31 100644
--- a/testing/web-platform/tests/css/css-view-transitions/object-view-box-old-image.html
+++ b/testing/web-platform/tests/css/css-view-transitions/object-view-box-old-image.html
@@ -60,6 +60,8 @@ html::view-transition-old(target) {
 <div id=hidden class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() =>  requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-captures-clip-path.html b/testing/web-platform/tests/css/css-view-transitions/old-content-captures-clip-path.html
index 3fa29ebb4bce..ac6200da16b2 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-captures-clip-path.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-captures-clip-path.html
@@ -33,6 +33,8 @@ html::view-transition { background: lightpink; }
 </style>
 <div id=e1 class=box></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     e1.classList.add("dst");
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-captures-different-size.html b/testing/web-platform/tests/css/css-view-transitions/old-content-captures-different-size.html
index be401fdef749..8bfa2407e511 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-captures-different-size.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-captures-different-size.html
@@ -49,6 +49,8 @@ html::view-transition { background: lightpink; }
 <div id=e2 class=box>two</div>
 <div id=e3 class=box>three</div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     e1.classList.add("dst");
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-captures-opacity.html b/testing/web-platform/tests/css/css-view-transitions/old-content-captures-opacity.html
index 8aaf4de053af..a1d976d5f5be 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-captures-opacity.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-captures-opacity.html
@@ -33,6 +33,8 @@ html::view-transition { background: lightpink; }
 <div id=e2 class=box>two</div>
 <div id=e3 class=box>three</div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     e1.classList.add("dst");
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-captures-root.html b/testing/web-platform/tests/css/css-view-transitions/old-content-captures-root.html
index 9129258fcaf7..067c049818e0 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-captures-root.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-captures-root.html
@@ -38,6 +38,8 @@ html::view-transition-new(root) { animation: unset; opacity: 0 }
 <div id=e1 class=box></div>
 <div id=shared></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     e1.classList.add("dst");
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-container-writing-modes.html b/testing/web-platform/tests/css/css-view-transitions/old-content-container-writing-modes.html
index 6f20465ff58e..2c487440ac79 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-container-writing-modes.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-container-writing-modes.html
@@ -73,6 +73,8 @@ html::view-transition { background: lightpink; }
 <div class=rl><div id=three class=shared>T</div></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     one.remove();
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-element-writing-modes.html b/testing/web-platform/tests/css/css-view-transitions/old-content-element-writing-modes.html
index f22dcb7a5464..87a736d12422 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-element-writing-modes.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-element-writing-modes.html
@@ -73,6 +73,8 @@ html::view-transition { background: lightpink; }
 <div id=three class="shared rl">T</div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     one.remove();
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-has-scrollbars.html b/testing/web-platform/tests/css/css-view-transitions/old-content-has-scrollbars.html
index 477fff7451d8..f87a4498c17e 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-has-scrollbars.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-has-scrollbars.html
@@ -43,6 +43,8 @@
 
 <div></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 // Ensure a root snapshot captured on a page with scrollbars uses the full
 // viewport size (including scrollbars). Areas obscured by scrollbars should be
 // filled with background and content; the snapshot should not be scaled-to-fit.
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-intrinsic-aspect-ratio.html b/testing/web-platform/tests/css/css-view-transitions/old-content-intrinsic-aspect-ratio.html
index 55436b807121..8ba2a8f31fad 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-intrinsic-aspect-ratio.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-intrinsic-aspect-ratio.html
@@ -55,6 +55,8 @@ html::view-transition { background: lightpink; }
 <div id=target2 class=box></div>
 <div id=hidden></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-is-empty-div.html b/testing/web-platform/tests/css/css-view-transitions/old-content-is-empty-div.html
index ced52af8fc58..c6a6655a78b3 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-is-empty-div.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-is-empty-div.html
@@ -45,6 +45,8 @@ html::view-transition { background: lightpink; }
 <div id=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   empty.style.viewTransitionName = "shared";
   document.startViewTransition(() => {
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-object-fit-fill.html b/testing/web-platform/tests/css/css-view-transitions/old-content-object-fit-fill.html
index 75dc628f944d..a3f146f9fecd 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-object-fit-fill.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-object-fit-fill.html
@@ -65,6 +65,8 @@ html::view-transition { background: lightpink; }
 <div id=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-object-fit-none.html b/testing/web-platform/tests/css/css-view-transitions/old-content-object-fit-none.html
index c40ad13435a7..592b89949bda 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-object-fit-none.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-object-fit-none.html
@@ -58,6 +58,8 @@ html::view-transition { background: lightpink; }
 <div id=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-clip-path-reference.html b/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-clip-path-reference.html
index 375b0128cc53..a9bbf0ff2472 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-clip-path-reference.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-clip-path-reference.html
@@ -83,6 +83,8 @@ html::view-transition { background: lightpink; }
 </svg>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-clip-path.html b/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-clip-path.html
index a4292558c7f9..04d4f31670f8 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-clip-path.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-clip-path.html
@@ -72,6 +72,8 @@ html::view-transition { background: lightpink; }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-overflow.html b/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-overflow.html
index 8a83a7ea7541..e5bfee912d99 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-overflow.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-object-view-box-overflow.html
@@ -55,6 +55,8 @@ html::view-transition { background: lightpink; }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-with-overflow-zoomed.html b/testing/web-platform/tests/css/css-view-transitions/old-content-with-overflow-zoomed.html
index 6e6196e65392..d78c424662a1 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-with-overflow-zoomed.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-with-overflow-zoomed.html
@@ -45,6 +45,8 @@ html::view-transition { background: lightpink; }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-content-with-overflow.html b/testing/web-platform/tests/css/css-view-transitions/old-content-with-overflow.html
index 3d8afc16e520..3ddf818c7896 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-content-with-overflow.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-content-with-overflow.html
@@ -40,6 +40,8 @@ html::view-transition { background: lightpink; }
 </div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() =>
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot)));
diff --git a/testing/web-platform/tests/css/css-view-transitions/old-root-vertical-writing-mode.html b/testing/web-platform/tests/css/css-view-transitions/old-root-vertical-writing-mode.html
index 4fd610b7addd..af4fcf5bb26e 100644
--- a/testing/web-platform/tests/css/css-view-transitions/old-root-vertical-writing-mode.html
+++ b/testing/web-platform/tests/css/css-view-transitions/old-root-vertical-writing-mode.html
@@ -57,6 +57,8 @@ html::view-transition-old(root) { animation: unset; opacity: 1; }
 <div id=two class=shared></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     one.remove();
diff --git a/testing/web-platform/tests/css/css-view-transitions/pseudo-computed-style-stays-in-sync-with-new-element.html b/testing/web-platform/tests/css/css-view-transitions/pseudo-computed-style-stays-in-sync-with-new-element.html
index b1ed783b0af4..103dc31930ca 100644
--- a/testing/web-platform/tests/css/css-view-transitions/pseudo-computed-style-stays-in-sync-with-new-element.html
+++ b/testing/web-platform/tests/css/css-view-transitions/pseudo-computed-style-stays-in-sync-with-new-element.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: computed style on pseudo-element stays in sync with the DOM element</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -21,6 +21,7 @@ div {
 
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     let transition = document.startViewTransition();
     await transition.domUpdated;
diff --git a/testing/web-platform/tests/css/css-view-transitions/pseudo-get-computed-style.html b/testing/web-platform/tests/css/css-view-transitions/pseudo-get-computed-style.html
index e837d52a5709..45d2559b3e78 100644
--- a/testing/web-platform/tests/css/css-view-transitions/pseudo-get-computed-style.html
+++ b/testing/web-platform/tests/css/css-view-transitions/pseudo-get-computed-style.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>Shared transitions: check pseudo element's display property</title>
 <link rel="help" href="https://github.com/WICG/view-transitions">
 <link rel="author" href="mailto:vmpstr@chromium.org">
@@ -24,6 +24,7 @@ div {
 
 <script>
 promise_test(() => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     let transition = document.startViewTransition(() => {
       assert_equals(getComputedStyle(document.documentElement, ":view-transition").position, "fixed", ":view-transition");
@@ -54,6 +55,7 @@ promise_test(() => {
 }, "position property of pseudo elements");
 
 promise_test(() => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     let transition = document.startViewTransition(() => {
       assert_equals(getComputedStyle(document.documentElement, ":view-transition").position, "fixed");
diff --git a/testing/web-platform/tests/css/css-view-transitions/ready_resolves_after_dom_before_raf.html b/testing/web-platform/tests/css/css-view-transitions/ready_resolves_after_dom_before_raf.html
index 9c0a68e292e5..3bc1822314cb 100644
--- a/testing/web-platform/tests/css/css-view-transitions/ready_resolves_after_dom_before_raf.html
+++ b/testing/web-platform/tests/css/css-view-transitions/ready_resolves_after_dom_before_raf.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>Shared transitions: promise resolution ordering</title>
 <link rel="help" href="https://github.com/WICG/view-transitions">
 <link rel="author" href="mailto:vmpstr@chromium.org">
@@ -24,6 +24,7 @@ div {
 
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise((resolve, reject) => {
     let dom_change_ran = false;
     let transition = document.startViewTransition(() => {
diff --git a/testing/web-platform/tests/css/css-view-transitions/root-captured-as-different-tag.html b/testing/web-platform/tests/css/css-view-transitions/root-captured-as-different-tag.html
index 36f60cfb5203..a8f3493d67c4 100644
--- a/testing/web-platform/tests/css/css-view-transitions/root-captured-as-different-tag.html
+++ b/testing/web-platform/tests/css/css-view-transitions/root-captured-as-different-tag.html
@@ -43,6 +43,8 @@ html::view-transition-image-pair(root) { visibility: hidden; }
 <div id=e1 class=box></div>
 <div id=shared></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     e1.classList.add("dst");
diff --git a/testing/web-platform/tests/css/css-view-transitions/root-scrollbar-with-fixed-background.html b/testing/web-platform/tests/css/css-view-transitions/root-scrollbar-with-fixed-background.html
index 52f35e7ed629..9a4684c3476a 100644
--- a/testing/web-platform/tests/css/css-view-transitions/root-scrollbar-with-fixed-background.html
+++ b/testing/web-platform/tests/css/css-view-transitions/root-scrollbar-with-fixed-background.html
@@ -50,6 +50,8 @@ html::view-transition-old(*) {
 <div id=first></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   await waitForAtLeastOneFrame();
 
diff --git a/testing/web-platform/tests/css/css-view-transitions/root-style-change-during-animation.html b/testing/web-platform/tests/css/css-view-transitions/root-style-change-during-animation.html
index 6a1786836a8e..b030d38ab1a6 100644
--- a/testing/web-platform/tests/css/css-view-transitions/root-style-change-during-animation.html
+++ b/testing/web-platform/tests/css/css-view-transitions/root-style-change-during-animation.html
@@ -47,6 +47,8 @@ html::view-transition-group(root) {
 <div id=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 function flipClass() {
   document.documentElement.classList.add("test");
   requestAnimationFrame(takeScreenshot);
diff --git a/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-end.html b/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-end.html
index f24c300aef4c..6ba07bd9e62b 100644
--- a/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-end.html
+++ b/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-end.html
@@ -37,6 +37,8 @@ html::view-transition-old(*) { animation: unset; opacity: 1; }
 <div class=hidden></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     document.documentElement.style.viewTransitionName = "none";
diff --git a/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-incoming.html b/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-incoming.html
index c2def74e2487..0620e911cfaa 100644
--- a/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-incoming.html
+++ b/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-incoming.html
@@ -27,6 +27,8 @@ html::view-transition-old(*) { animation: unset; opacity: 0; }
 <div id=box></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     document.documentElement.style.viewTransitionName = "none";
diff --git a/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-start.html b/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-start.html
index 211985e7740f..0a1cb9617e45 100644
--- a/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-start.html
+++ b/testing/web-platform/tests/css/css-view-transitions/root-to-shared-animation-start.html
@@ -27,6 +27,8 @@ html::view-transition-old(*) { animation: unset; opacity: 1; }
 <div id=box></div>
 
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     document.documentElement.style.viewTransitionName = "none";
diff --git a/testing/web-platform/tests/css/css-view-transitions/set-universal-specificity.html b/testing/web-platform/tests/css/css-view-transitions/set-universal-specificity.html
index 95c0cfe04902..80dc8272b542 100644
--- a/testing/web-platform/tests/css/css-view-transitions/set-universal-specificity.html
+++ b/testing/web-platform/tests/css/css-view-transitions/set-universal-specificity.html
@@ -34,6 +34,8 @@ html::view-transition-new(root) { animation: unset; opacity: 0 }
 </style>
 <div id=shared></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 async function runTest() {
   document.startViewTransition(() => {
     requestAnimationFrame(() => requestAnimationFrame(takeScreenshot));
diff --git a/testing/web-platform/tests/css/css-view-transitions/style-inheritance.html b/testing/web-platform/tests/css/css-view-transitions/style-inheritance.html
index f896f23be515..bfa110b22f59 100644
--- a/testing/web-platform/tests/css/css-view-transitions/style-inheritance.html
+++ b/testing/web-platform/tests/css/css-view-transitions/style-inheritance.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: ensure correct style inheritance for pseudo tree</title>
 <link rel="help" href="https://github.com/WICG/view-transitions">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -29,6 +29,7 @@
 
 <script>
 promise_test(() => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     let transition = document.startViewTransition();
     transition.ready.then(() => {
diff --git a/testing/web-platform/tests/css/css-view-transitions/synchronous-callback-skipped-before-run.html b/testing/web-platform/tests/css/css-view-transitions/synchronous-callback-skipped-before-run.html
index 1bda243449c5..d1ada87e9d6a 100644
--- a/testing/web-platform/tests/css/css-view-transitions/synchronous-callback-skipped-before-run.html
+++ b/testing/web-platform/tests/css/css-view-transitions/synchronous-callback-skipped-before-run.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: skipTransition() invoked before a synchronous updateDOM callback is invoked</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -20,6 +20,7 @@ div {
 
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     let transition = document.startViewTransition(() => {
       first.style.viewTransitionName = "target";
diff --git a/testing/web-platform/tests/css/css-view-transitions/transition-skipped-after-animation-started.html b/testing/web-platform/tests/css/css-view-transitions/transition-skipped-after-animation-started.html
index 78f32def3e58..56c477a55f6e 100644
--- a/testing/web-platform/tests/css/css-view-transitions/transition-skipped-after-animation-started.html
+++ b/testing/web-platform/tests/css/css-view-transitions/transition-skipped-after-animation-started.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: skipTransition() after animations have started running should resolve finished promise</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -25,6 +25,7 @@ div {
 
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     let transition = document.startViewTransition();
     await transition.ready;
diff --git a/testing/web-platform/tests/css/css-view-transitions/transition-skipped-from-invalid-callback.html b/testing/web-platform/tests/css/css-view-transitions/transition-skipped-from-invalid-callback.html
index 4a56f81efe0f..0dd098cbdfaa 100644
--- a/testing/web-platform/tests/css/css-view-transitions/transition-skipped-from-invalid-callback.html
+++ b/testing/web-platform/tests/css/css-view-transitions/transition-skipped-from-invalid-callback.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: transition skipped in animation phase</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -25,6 +25,7 @@ div {
 
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     let transition = document.startViewTransition(() => {
       let foo = bar;
diff --git a/testing/web-platform/tests/css/css-view-transitions/unset-and-initial-view-transition-name.html b/testing/web-platform/tests/css/css-view-transitions/unset-and-initial-view-transition-name.html
index 93c8eb64d79a..4ff5c05316bd 100644
--- a/testing/web-platform/tests/css/css-view-transitions/unset-and-initial-view-transition-name.html
+++ b/testing/web-platform/tests/css/css-view-transitions/unset-and-initial-view-transition-name.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: validates that view-transition-name: unset or initial are ignored</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -35,6 +35,7 @@
 
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     let transition = document.startViewTransition();
     await transition.domUpdated;
diff --git a/testing/web-platform/tests/css/css-view-transitions/view-transition-name-on-added-element.html b/testing/web-platform/tests/css/css-view-transitions/view-transition-name-on-added-element.html
index cd957973b7d9..643121e81854 100644
--- a/testing/web-platform/tests/css/css-view-transitions/view-transition-name-on-added-element.html
+++ b/testing/web-platform/tests/css/css-view-transitions/view-transition-name-on-added-element.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: ensures view-transition-name is tracked on element added by script</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -22,6 +22,7 @@
 </body>
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise((resolve, reject) => {
     // Remove and add an uncontained element. Even though this element doesn't
     // create a stacking context its verified during the transition.
diff --git a/testing/web-platform/tests/css/css-view-transitions/view-transition-name-on-removed-element.html b/testing/web-platform/tests/css/css-view-transitions/view-transition-name-on-removed-element.html
index 4a26a8154f5d..36beb308283a 100644
--- a/testing/web-platform/tests/css/css-view-transitions/view-transition-name-on-removed-element.html
+++ b/testing/web-platform/tests/css/css-view-transitions/view-transition-name-on-removed-element.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html class=reftest-wait>
+<html>
 <title>View transitions: ensures view-transition-name is not tracked on element removed by script</title>
 <link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
 <link rel="author" href="mailto:khushalsagar@chromium.org">
@@ -22,6 +22,7 @@
 </body>
 <script>
 promise_test(async t => {
+  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
   return new Promise(async (resolve, reject) => {
     // Remove an uncontained element. Because this element is not visited when
     // discovering named elements, the transition is not skipped.
diff --git a/testing/web-platform/tests/css/css-view-transitions/web-animations-api.html b/testing/web-platform/tests/css/css-view-transitions/web-animations-api.html
index 0c7e485723a1..b9d62fabc6b3 100644
--- a/testing/web-platform/tests/css/css-view-transitions/web-animations-api.html
+++ b/testing/web-platform/tests/css/css-view-transitions/web-animations-api.html
@@ -32,6 +32,8 @@ html::view-transition-old(*) {
 <div id=first></div>
 <div id=second></div>
 <script>
+failIfNot(document.startViewTransition, "Missing document.startViewTransition");
+
 function setAnimation() {
   document.documentElement.animate({ transform: ['translate(100px)', 'translate(100px)'] }, { duration: 10000, pseudoElement: '::view-transition-group(first)'});
   document.documentElement.animate({ transform: ['translate(150px)', 'translate(150px)'] }, { duration: 10000, pseudoElement: '::view-transition-group(second)'});
-- 
2.11.4.GIT