Send hardware video frames with mailboxes.

cc/layers/video_layer_impl.h

Index: cc/layers/video_layer_impl.h
diff --git a/cc/layers/video_layer_impl.h b/cc/layers/video_layer_impl.h
index 5ccc11b98498445c599eb8630391dc14fc37d8c5..b07187115edfa250ba3ab57bf3656f8232f33ea3 100644
--- a/cc/layers/video_layer_impl.h
+++ b/cc/layers/video_layer_impl.h
@@ -56,10 +56,6 @@ class CC_EXPORT VideoLayerImpl : public LayerImpl {
   VideoFrameExternalResources::ResourceType frame_resource_type_;
   std::vector<ResourceProvider::ResourceId> frame_resources_;
 
-  // TODO(danakj): Remove this when hardware frames come through a mailbox.
-  unsigned hardware_resource_;
-  TextureMailbox::ReleaseCallback hardware_release_callback_;
-
   // TODO(danakj): Remove these, hide software path inside ResourceProvider and
   // ExternalResource (aka TextureMailbox) classes.
   std::vector<unsigned> software_resources_;