[webkit-changes] [WebKit/WebKit] 282f60: Canvas will intermittently come up blurry and rema...

[mattwoodrow]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 282f6081046755e5574790109a9deb0fa50d9fa9
      https://github.com/WebKit/WebKit/commit/282f6081046755e5574790109a9deb0fa50d9fa9
  Author: Matt Woodrow <mattwoodrow at apple.com>
  Date:   2023-05-30 (Tue, 30 May 2023)

  Changed paths:
    M Source/WebCore/rendering/RenderLayerBacking.cpp

  Log Message:
  -----------
  Canvas will intermittently come up blurry and remain so.
https://bugs.webkit.org/show_bug.cgi?id=256260

Reviewed by Simon Fraser.

The unscaled bitmap optimization uses backing stores that don't have device scaling applied, when the result would be identical.
We need to make sure it gets re-evaluated if the size of the canvas backing store changes, this patch makes sure we schedule a compositing layer update for that to happen.

I haven't found a way to test this yet, capturing the layer tree as text (as other tests of this feature do) implicitly forces a compositing layer update, hiding the bug.

* Source/WebCore/rendering/RenderLayerBacking.cpp:
(WebCore::RenderLayerBacking::contentChanged):

Canonical link: https://commits.webkit.org/264699@main