[chromium] Write unit tests for compositor-thread zooming

[chromium] Write unit tests for compositor-thread zooming
https://bugs.webkit.org/show_bug.cgi?id=71529

Patch by Alexandre Elias <aelias@google.com> on 2012-01-20
Reviewed by James Robinson.

Add unit tests for pinch zoom and page scale animation.  Includes
small cleanups in CCLayerTreeHostImpl for testability.

Source/WebCore:

* platform/graphics/chromium/cc/CCInputHandler.h:
* platform/graphics/chromium/cc/CCLayerTreeHostImpl.cpp:
(WebCore::CCLayerTreeHostImpl::startPageScaleAnimation):
(WebCore::CCLayerTreeHostImpl::setViewportSize):
* platform/graphics/chromium/cc/CCLayerTreeHostImpl.h:

Source/WebKit/chromium:

* tests/CCLayerTreeHostImplTest.cpp:
(WebKit::CCLayerTreeHostImplTest::setupScrollAndContentsLayers):
(WebKit::TEST_F):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@105566 268f45cc-cd09-0410-ab3c-d52691b4dbfc