[chromium] Use opaque contents for paint culling

[chromium] Use opaque contents for paint culling
https://bugs.webkit.org/show_bug.cgi?id=81676

Patch by Dana Jansens <danakj@chromium.org> on 2012-03-20
Reviewed by Adrienne Walker.

Source/WebCore:

UnitTest: CCLayerTreeHostTestContentLayerOcclusion

* platform/graphics/chromium/cc/CCLayerTreeHost.cpp:
(WebCore::CCLayerTreeHost::paintLayerContents):

Source/WebKit/chromium:

* tests/CCLayerTreeHostTest.cpp:
(WTF::TestLayerChromium::opaqueContentsRegion):
(WTF::TestLayerChromium::setOpaqueContentsRect):
(TestLayerChromium):
(CCLayerTreeHostTestContentLayerOcclusion):
(WTF::CCLayerTreeHostTestContentLayerOcclusion::CCLayerTreeHostTestContentLayerOcclusion):
(WTF::CCLayerTreeHostTestContentLayerOcclusion::beginTest):
(WTF::CCLayerTreeHostTestContentLayerOcclusion::afterTest):
(WTF):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@111426 268f45cc-cd09-0410-ab3c-d52691b4dbfc