Merge 109263 - [chromium] Don't let invalidation for next frame prevent tile upload

Merge 109263 - [chromium] Don't let invalidation for next frame prevent tile upload
https://bugs.webkit.org/show_bug.cgi?id=79841

Patch by Dana Jansens <danakj@chromium.org>; on 2012-02-29
Reviewed by James Robinson.

Source/WebCore:

We currently don't push dirty tiles to the impl thread so there are no
tiles with garbage data on the impl thread. However, this judgement is
overzealous and blocks tiles that get invalidated by WebKit for the
next frame during the paint of the current frame.

Instead, check if a tile is dirty and was not painted for the current
frame when deciding to push the tile to the impl thread. This requires
that we know if a tile was painted during the current frame, which we
can do if we always reset m_updateRect to be empty each frame.

New unit tests: TiledLayerChromiumTest.pushTilesMarkedDirtyDuringPaint
                TiledLayerChromiumTest.pushTilesLayerMarkedDirtyDuringPaintOnNextLayer
                TiledLayerChromiumTest.pushTilesLayerMarkedDirtyDuringPaintOnPreviousLayer

* platform/graphics/chromium/TiledLayerChromium.cpp:
(WebCore::UpdatableTile::isDirtyForCurrentFrame):
(WebCore::TiledLayerChromium::pushPropertiesTo):
(WebCore::TiledLayerChromium::prepareToUpdateTiles):
(WebCore::TiledLayerChromium::resetUpdateState):
(WebCore):
(WebCore::TiledLayerChromium::prepareToUpdate):
* platform/graphics/chromium/TiledLayerChromium.h:
(TiledLayerChromium):

Source/WebKit/chromium:

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

TBR=commit-queue@webkit.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=110467