tree addb7b6b7f788a6b59303de28b7fbdd64379d9ac
parent f525eb5ae9cc7ce38f5f33b226e41a888b5a373f
author simon.fraser@apple.com <simon.fraser@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1557613354 +0000
committer simon.fraser@apple.com <simon.fraser@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1557613354 +0000

Layer bounds are incorrect for sharing layers that paint with transforms
https://bugs.webkit.org/show_bug.cgi?id=197768
<rdar://problem/50695493>

Reviewed by Zalan Bujtas.

Source/WebCore:

We don't need to traverse shared layers if the backing-provider has overflow clip,
because we know they are containing-block descendants and therefore clipped.

Note tha the CSS "clip" property doesn't guarantee this, because the clip rect
can be larger than the element, so in that case we just traverse shared layers.

Tests: compositing/shared-backing/sharing-bounds-clip.html
       compositing/shared-backing/sharing-bounds-non-clipping-shared-layer.html
       compositing/shared-backing/sharing-bounds-transformed-sharing-layer.html
       compositing/shared-backing/sharing-bounds.html

* rendering/RenderLayerBacking.cpp:
(WebCore::RenderLayerBacking::updateCompositedBounds):

LayoutTests:

Tests for backing-shared layer bounds in various configurations.

* compositing/shared-backing/sharing-bounds-clip-expected.txt: Added.
* compositing/shared-backing/sharing-bounds-clip.html: Added.
* compositing/shared-backing/sharing-bounds-expected.txt: Added.
* compositing/shared-backing/sharing-bounds-non-clipping-shared-layer-expected.txt: Added.
* compositing/shared-backing/sharing-bounds-non-clipping-shared-layer.html: Added.
* compositing/shared-backing/sharing-bounds-transformed-sharing-layer-expected.txt: Added.
* compositing/shared-backing/sharing-bounds-transformed-sharing-layer.html: Added.
* compositing/shared-backing/sharing-bounds.html: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@245208 268f45cc-cd09-0410-ab3c-d52691b4dbfc