Merge 120858 - [chromium] Separate LayerRenderer initialization from updateLayers

Merge 120858 - [chromium] Separate LayerRenderer initialization from updateLayers
https://bugs.webkit.org/show_bug.cgi?id=89525

Reviewed by Adrienne Walker.

Source/WebCore:

This adds an explicit call to initialize the layer renderer of a given CCLayerTreeHost instead of having it be
implicit in updateLayers(). This way the proxies can control the initialization sequence more closely and do
useful work between the two calls.

Refactor, no change in behavior. Covered by existing tests.

* platform/graphics/chromium/cc/CCLayerTreeHost.cpp:
(WebCore::CCLayerTreeHost::compositeAndReadback):
(WebCore::CCLayerTreeHost::initializeLayerRendererIfNeeded):
(WebCore):
(WebCore::CCLayerTreeHost::updateLayers):
* platform/graphics/chromium/cc/CCLayerTreeHost.h:
(CCLayerTreeHost):
* platform/graphics/chromium/cc/CCSingleThreadProxy.cpp:
(WebCore::CCSingleThreadProxy::commitAndComposite):
* platform/graphics/chromium/cc/CCThreadProxy.cpp:
(WebCore::CCThreadProxy::compositeAndReadback):
(WebCore::CCThreadProxy::beginFrame):

Source/WebKit/chromium:

Update tests to call initializeLayerRendererIfNeeded() before calling updateLayers() to reflect what the proxies
do.

* tests/CCLayerTreeHostTest.cpp:
(WTF::CCLayerTreeHostTestLayerOcclusion::beginTest):
(WTF::CCLayerTreeHostTestLayerOcclusionWithFilters::beginTest):
(WTF::CCLayerTreeHostTestManySurfaces::beginTest):
* tests/TiledLayerChromiumTest.cpp:

TBR=jamesr@google.com
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=122257