cc: Add main frame timing info to frame timing tracker.

cc/layers/layer_impl.cc

Index: cc/layers/layer_impl.cc
diff --git a/cc/layers/layer_impl.cc b/cc/layers/layer_impl.cc
index f74228bdacf694cca1ac36e0c2503da2ba4fc510..2b45f0b09ca7e424eb1cd39128bdd59e14e878d3 100644
--- a/cc/layers/layer_impl.cc
+++ b/cc/layers/layer_impl.cc
@@ -1016,6 +1016,11 @@ void LayerImpl::PassFrameTimingRequests(
   SetNeedsPushProperties();
 }
 
+void LayerImpl::GatherFrameTimingRequestIds(std::vector<int64_t>* request_ids) {
+  for (const auto& request : frame_timing_requests_)
+    request_ids->push_back(request.id());
+}
+
 void LayerImpl::SetTransform(const gfx::Transform& transform) {
   if (transform_ == transform)
     return;