From 7bf0eb676d49bf23413c7d7f415e6a436384f975 Mon Sep 17 00:00:00 2001
From: Xianzhu Wang <wangxianzhu@chromium.org>
Date: Mon, 22 Feb 2021 21:56:04 +0000
Subject: [PATCH] Bug 1693114 [wpt PR 27648] - [CompositeAfterPaint] Handle
 main thread scrolling change during scroll animation, a=testonly

Automatic update from web-platform-tests
[CompositeAfterPaint] Handle main thread scrolling change during scroll animation

In pre-CAP the situation is handled when composited scrolling layer
changes in CompositedLayerMapping during compositing assignments update.
Not sure how a mere main thread scrolling status change (e.g. adding
background-attachment:fixed to a composited scrolling scroller) is
handled, but a test for the situation passes.

For CAP, now check change of main thread scrolling status in
PaintPropertyTreeBuilder.

The original test for the situation has not been working since we
removed rounded corner as a blocker of composited scrolling. Fix and
modernize it and add wpt tests.

Bug: 1176543
Change-Id: I00595635a7b1a729ddd05173e3452e40c34e52b3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2688140
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#855835}

--

wpt-commits: 4c56f3ec2751ff5952b317be7e40844c7b6cf914
wpt-pr: 27648
---
 ...-attachment-fixed-during-smooth-scroll-ref.html | 21 ++++++++++
 ...ound-attachment-fixed-during-smooth-scroll.html | 46 ++++++++++++++++++++++
 .../background-change-during-smooth-scroll.html    | 46 ++++++++++++++++++++++
 3 files changed, 113 insertions(+)
 create mode 100644 testing/web-platform/tests/css/cssom-view/add-background-attachment-fixed-during-smooth-scroll-ref.html
 create mode 100644 testing/web-platform/tests/css/cssom-view/add-background-attachment-fixed-during-smooth-scroll.html
 create mode 100644 testing/web-platform/tests/css/cssom-view/background-change-during-smooth-scroll.html
diff --git a/testing/web-platform/tests/css/cssom-view/add-background-attachment-fixed-during-smooth-scroll-ref.html b/testing/web-platform/tests/css/cssom-view/add-background-attachment-fixed-during-smooth-scroll-ref.html
new file mode 100644
index 000000000000..8bcbf4110267
--- /dev/null
+++ b/testing/web-platform/tests/css/cssom-view/add-background-attachment-fixed-during-smooth-scroll-ref.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<title>Add background-attachment:fixed during smooth scroll</title>
+<style>
+#container {
+  width: 200px;
+  height: 200px;
+  overflow: scroll;
+  background: linear-gradient(green, blue);
+  background-attachment: fixed;
+}
+#content {
+  width: 7500px;
+  height: 7500px;
+}
+</style>
+<div id="container">
+  <div id="content">Content</div>
+</div>
+<script>
+container.scrollTop = 6000;
+</script>
diff --git a/testing/web-platform/tests/css/cssom-view/add-background-attachment-fixed-during-smooth-scroll.html b/testing/web-platform/tests/css/cssom-view/add-background-attachment-fixed-during-smooth-scroll.html
new file mode 100644
index 000000000000..61d8cd7bcb14
--- /dev/null
+++ b/testing/web-platform/tests/css/cssom-view/add-background-attachment-fixed-during-smooth-scroll.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<title>Add background-attachment:fixed during smooth scroll</title>
+<link rel="help" href="https://drafts.csswg.org/cssom-view/#dictdef-scrolltooptions">
+<link rel="match" href="add-background-attachment-fixed-during-smooth-scroll-ref.html">
+<script src="/common/reftest-wait.js"></script>
+<style>
+#container {
+  width: 200px;
+  height: 200px;
+  overflow: scroll;
+  background: linear-gradient(green, blue);
+  will-change: transform;
+}
+#content {
+  width: 7500px;
+  height: 7500px;
+}
+</style>
+<script>
+function startSmoothScroll() {
+  var scrollToOptions = {behavior: "smooth", top: 6000};
+  container.scrollTo(scrollToOptions);
+  requestAnimationFrame(preventCompositedScrolling);
+}
+
+function preventCompositedScrolling() {
+  container.style.backgroundAttachment = "fixed";
+  requestAnimationFrame(waitForSmoothScrollEnd);
+}
+
+function waitForSmoothScrollEnd() {
+  if (container.scrollTop == 6000) {
+    takeScreenshot();
+  } else {
+    window.requestAnimationFrame(waitForSmoothScrollEnd);
+  }
+}
+
+onload = () => {
+  requestAnimationFrame(startSmoothScroll);
+}
+</script>
+<div id="container">
+  <div id="content">Content</div>
+</div>
diff --git a/testing/web-platform/tests/css/cssom-view/background-change-during-smooth-scroll.html b/testing/web-platform/tests/css/cssom-view/background-change-during-smooth-scroll.html
new file mode 100644
index 000000000000..b5c28c77f8e5
--- /dev/null
+++ b/testing/web-platform/tests/css/cssom-view/background-change-during-smooth-scroll.html
@@ -0,0 +1,46 @@
+<!DOCTYPE html>
+<title>Background change from opaque to transparent during smooth scroll</title>
+<link rel=help href="https://drafts.csswg.org/cssom-view/#dictdef-scrolltooptions">
+<style>
+#container {
+  width: 200px;
+  height: 200px;
+  overflow: scroll;
+  background: white;
+}
+#content {
+  width: 7500px;
+  height: 7500px;
+}
+</style>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+var t = async_test('background change during smooth scroll');
+
+function startSmoothScroll() {
+  var scrollToOptions = {behavior: "smooth", top: 6000};
+  container.scrollTo(scrollToOptions);
+  requestAnimationFrame(preventCompositedScrolling);
+}
+
+function preventCompositedScrolling() {
+  container.style.background = "transparent";
+  requestAnimationFrame(waitForSmoothScrollEnd);
+}
+
+function waitForSmoothScrollEnd() {
+  if (container.scrollTop == 6000) {
+    t.done();
+  } else {
+    window.requestAnimationFrame(waitForSmoothScrollEnd);
+  }
+}
+
+onload = () => {
+  requestAnimationFrame(startSmoothScroll);
+}
+</script>
+<div id="container">
+  <div id="content">Content</div>
+</div>
-- 
2.11.4.GIT

