Bug 1008301 - Don't invalidate when the visible region of a layer changes. r=roc
Bug 1008301 - Invalidate when a layer's pre or post scale changes. r=roc
Bug 1008301 - Add invalidation logging for layer scale change invalidations. r=roc
Bug 1008301 - Make DisplayItemClip only invalidate changes in clip, not changes in bounds. r=roc
Bug 1008578 - Don't invalidate everything when a scrollframe becomes inactive. r=roc