Merge 112568 - [chromium] Ensure framebuffer exists at the start of beginDrawingFrame.

Merge 112568 - [chromium] Ensure framebuffer exists at the start of beginDrawingFrame.
https://bugs.webkit.org/show_bug.cgi?id=82569

Patch by Michal Mocny <mmocny@google.com>; on 2012-03-29
Reviewed by James Robinson.

Source/WebCore:

Updated LayerRendererChromiumTest unittests.

* platform/graphics/chromium/LayerRendererChromium.cpp:
(WebCore::LayerRendererChromium::setVisible):
(WebCore::LayerRendererChromium::beginDrawingFrame):
* platform/graphics/chromium/LayerRendererChromium.h:
* platform/graphics/chromium/cc/CCSingleThreadProxy.cpp:
(WebCore::CCSingleThreadProxy::compositeAndReadback):
* platform/graphics/chromium/cc/CCThreadProxy.cpp:
(WebCore::CCThreadProxy::compositeAndReadback):
(WebCore::CCThreadProxy::requestReadbackOnImplThread):

Source/WebKit/chromium:

* tests/LayerRendererChromiumTest.cpp:
(FakeLayerRendererChromiumClient::FakeLayerRendererChromiumClient):
(FakeLayerRendererChromiumClient::rootLayer):
(FakeLayerRendererChromiumClient):
(TEST_F):

TBR=commit-queue@webkit.org
BUG=120589
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=112693