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 695f539b5ea62f944a4ffe35bec48a899b06749b..fa1f06ea2e2d9eac163307acae49a1a97ecc62ff 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -658,7 +658,7 @@ 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