[chromium] Add overdraw metrics for texture uploads

[chromium] Add overdraw metrics for texture uploads
https://bugs.webkit.org/show_bug.cgi?id=81175

Patch by Dana Jansens <danakj@chromium.org> on 2012-03-16
Reviewed by Adrienne Walker.

Source/WebCore:

Record texture upload metrics during paint. To properly record
the amount of pixels culled, we must compute the amount of pixels we
would have uploaded for a tile. This requires knowing the dirty rect of
the tile, but the dirty rect can be changed by WebKit during a paint, so
we always store the dirtyRect in the tile's updateRect. We add an
m_updateCulled bool to the UpdatableTile structure, to identify tiles
that were not updated, and know a tile was updated if updateRect is not
empty and updateCulled is false.

Tested by all TiledLayerChromiumTests that use occlusion tracker.

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

Source/WebKit/chromium:

* tests/TiledLayerChromiumTest.cpp:
(WTF::TEST):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@111023 268f45cc-cd09-0410-ab3c-d52691b4dbfc