Merge 106459 - Fix the semantics of passing contentsVisible flag to GraphicsLayers

Merge 106459 - Fix the semantics of passing contentsVisible flag to GraphicsLayers
https://bugs.webkit.org/show_bug.cgi?id=76975

Reviewed by Simon Fraser.

Source/WebCore:

This patch is covered by existing tests, in particular
compositing/visibility/layer-visible-content.html; its
expectations are rebaselined.

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

LayoutTests:

* compositing/visibility/layer-visible-content-expected.txt: rebaselined expected result
* compositing/visibility/layer-visible-content.html: fixed height so that result is platform-independent
* platform/chromium/test_expectations.txt: removed fail expectation, it should pass now.


TBR=shawnsingh@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=106841