Add Mojo API for Blink hit testing

components/viz/service/frame_sinks/direct_layer_tree_frame_sink.cc

Index: components/viz/service/frame_sinks/direct_layer_tree_frame_sink.cc
diff --git a/components/viz/service/frame_sinks/direct_layer_tree_frame_sink.cc b/components/viz/service/frame_sinks/direct_layer_tree_frame_sink.cc
index c4540aa4cc93760f9b02e1ee27431f7cbbb565b6..957653028c6219929a49dd1759bb1f88bf78a55b 100644
--- a/components/viz/service/frame_sinks/direct_layer_tree_frame_sink.cc
+++ b/components/viz/service/frame_sinks/direct_layer_tree_frame_sink.cc
@@ -75,7 +75,8 @@ bool DirectLayerTreeFrameSink::BindToClient(
   constexpr bool is_root = true;
   constexpr bool handles_frame_sink_id_invalidation = false;
   support_ = support_manager_->CreateCompositorFrameSinkSupport(
-      this, frame_sink_id_, is_root, handles_frame_sink_id_invalidation,
+      this, nullptr, frame_sink_id_, is_root,

[Navid Zolghadr, 2017/08/09 16:08:22]

There are some places like this that were not being reached as the result of
CreateForWidget. So I wouldn't have the hit test interface instance. I wasn't
sure what to do with these and when each of those cases happen. Any idea?

+      handles_frame_sink_id_invalidation,
       capabilities_.delegated_sync_points_required);
   begin_frame_source_ = base::MakeUnique<ExternalBeginFrameSource>(this);
   client_->SetBeginFrameSource(begin_frame_source_.get());