Bug 1788846 [wpt PR 35713] - Reduce cost if transform-based overscroll isn't enabled...

Bug 1788846 [wpt PR 35713] - Reduce cost if transform-based overscroll isn't enabled, a=testonly

Automatic update from web-platform-tests
Reduce cost if transform-based overscroll isn't enabled

When transform-based overscroll isn't enabled,
- don't create VisualViewport::elastic_overscroll_transform_node_
- don't composite PaintOffsetTranslation() for fixed-position objects
  in a non-scrollable viewport.

This will slightly reduce cost on platforms that don't use
transform-based overscroll, and simpify code by letting cc check
cc::TransformNode::should_undo_overscroll.

Bug: 877794, 1356555
Change-Id: I0b8b3b031418ed56470b5e891651732be0ca0b6d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3860093
Reviewed-by: Rahul Arakeri <arakeri@microsoft.com>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1042285}

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wpt-commits: f225fb1eeee7c9aa54d85609a5d30949b923a10a
wpt-pr: 35713