Store recording invalidations in DisplayListRecordingSource, save them via Update.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index a12fb282fcaa9d25e9657de44290d5762639e97b..4f5ce1595198b0743f6262b5eec389c00d59a7ec 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -653,7 +653,7 @@ skia::RefPtr<SkPicture> PictureLayerImpl::GetPicture() {
   return raster_source_->GetFlattenedPicture();
 }
 
-Region PictureLayerImpl::GetInvalidationRegion() {
+Region PictureLayerImpl::GetInvalidationRegionForDebugging() {
   // |invalidation_| gives the invalidation contained in the source frame, but
   // is not cleared after drawing from the layer. However, update_rect() is
   // cleared once the invalidation is drawn, which is useful for debugging