cc: Provide notifications when resources are available.

cc/layers/delegated_renderer_layer.cc

Index: cc/layers/delegated_renderer_layer.cc
diff --git a/cc/layers/delegated_renderer_layer.cc b/cc/layers/delegated_renderer_layer.cc
index cc49c753e25a7ec58322b7f268b9c491ee66baca..edc2e8461704a9109b4fbad90b7a570e19f51f49 100644
--- a/cc/layers/delegated_renderer_layer.cc
+++ b/cc/layers/delegated_renderer_layer.cc
@@ -105,6 +105,8 @@ void DelegatedRendererLayer::SetFrameData(
     TransferableResource::ReturnResources(
         frame_data_->resource_list,
         &unused_resources_for_child_compositor_);
+    if (client_)
+      client_->UnusedResourcesAreAvailable();
   }
   frame_data_ = new_frame_data.Pass();
   if (!frame_data_->render_pass_list.empty()) {
@@ -154,6 +156,8 @@ void DelegatedRendererLayer::ReceiveUnusedResources(
       unused_resources_for_child_compositor_.end(),
       unused.begin(),
       unused.end());
+  if (client_)
+    client_->UnusedResourcesAreAvailable();
 }
 
 // static