Merge 106732 - [chromium] Fix multi-second hangs in compositor invalidating large layers

Merge 106732 - [chromium] Fix multi-second hangs in compositor invalidating large layers
https://bugs.webkit.org/show_bug.cgi?id=77774

Reviewed by James Robinson.

Correctness covered by existing tests.

* platform/graphics/chromium/TiledLayerChromium.cpp:
(WebCore::TiledLayerChromium::pushPropertiesTo):
Remove tiles from the tiler when they are invalid (ie., no longer have
texture backing).
(WebCore::TiledLayerChromium::invalidateRect):
Instead of iterating over the tile indices (which may be very large),
iterate over the tile hash map instead.


TBR=senorblanco@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=106813