Flash of white when exiting full screen HTML5 video
Created attachment 139923 [details]
Comment on attachment 139923 [details]
Is it possible to make a test for this?
We could make a manual test. But there's no way to write a DRT or WKRT automated test for this.
After making a test case for this patch, i see that the flash is still occurring. (though less often, & with a shorter flash.) Pulling this patch and investigating further.
This looks like a problem with the TiledCoreAnimationDrawingAreaProxy. When attempting to sync up drawing between the UIProcess and the WebProcess, this patch calls WebPageProxy::forceRepaint(), which in turn calls m_drawingArea->waitForBackingStoreUpdateOnNextPaint();
The drawing area in question is a TiledCoreAnimationDrawingAreaProxy, and it doesn't implement waitForBackingStoreUpdateOnNextPaint(), it gets effectively ignored.
Indeed, if I disable tiled drawing and full page acceleration, the flashing problem disappears.
Created attachment 140359 [details]
Committed r116188: <http://trac.webkit.org/changeset/116188>