Bug 1000875 - Give nsDOMWindowUtils::CheckAndClearPaintedState the ability to check paints of canvas frames. r=roc
Bug 1000875 - Improve test_fixed_bg_scrolling_repaints.html. r=roc
Bug 1000875 - Add invalidation debugging annotations for layer content type changes. r=roc
Bug 1000875 - Add invalidation debugging annotations for changes of a layer's forced background color. r=roc
Bug 1000875 - Fix nsDisplayBackgroundImage::GetInsideClipRegion calculation for canvas frames. r=roc

The opaque region of the background image display item was incorrectly clipped to the viewport size, offset by the scroll position. nsDisplayBackgroundImage::GetBoundsInternal has a special case for canvas frames that sets the clip area to the whole canvas area; this patch does the same for GetInsideClipRegion.