am d253060c: Merge "Fix repaint bug. In some cases when the content size changes...

* commit 'd253060c6edf139871ea630f884cc6631a162854':
  Fix repaint bug. In some cases when the content size changes, the inval rects we receive from webkit do not fully cover the area that changed. For now, fix this by forcing the invalidation of the entire content (note: we only invalidate the tiles -- we do not force an actual regeneration of the pictureset for the entire content)