[cc] Add and plumb CFS::DidNotProduceFrame.

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 05f4c7d964289c7b85260da91a6ffaf1559d45ed..6df3ba41326f798683f83521bb8799a554e3ef71 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -1939,6 +1939,10 @@ void LayerTreeHostImpl::DidFinishImplFrame() {
   decoded_image_tracker_.NotifyFrameFinished();
 }
 
+void LayerTreeHostImpl::BeginFrameDidNotProduceFrame(const BeginFrameAck& ack) {
+  compositor_frame_sink_->BeginFrameDidNotProduceFrame(ack);

[sunnyps, 2017/05/22 07:17:12]

nit: Check if compositor_frame_sink_ is non-null because the CFS can be lost.

[Eric Seckler, 2017/05/22 11:29:58]

Done.

+}
+
 void LayerTreeHostImpl::UpdateViewportContainerSizes() {
   LayerImpl* inner_container = active_tree_->InnerViewportContainerLayer();
   LayerImpl* outer_container = active_tree_->OuterViewportContainerLayer();