Add LatencyInfo support for Surfaces.

cc/surfaces/surface_aggregator.cc

Index: cc/surfaces/surface_aggregator.cc
diff --git a/cc/surfaces/surface_aggregator.cc b/cc/surfaces/surface_aggregator.cc
index 5ddd832d09a6b31fb813559819f624d011fb65c8..d9ec2961cee0915bdf01bb2b42e88211fc2a6eb9 100644
--- a/cc/surfaces/surface_aggregator.cc
+++ b/cc/surfaces/surface_aggregator.cc
@@ -346,6 +346,14 @@ scoped_ptr<CompositorFrame> SurfaceAggregator::Aggregate(SurfaceId surface_id) {
   contained_surfaces_.swap(previous_contained_surfaces_);
   contained_surfaces_.clear();
 
+  for (SurfaceIndexMap::iterator it = previous_contained_surfaces_.begin();
+       it != previous_contained_surfaces_.end();
+       ++it) {
+    Surface* surface = manager_->GetSurfaceForId(it->first);
+    if (surface)
+      surface->TakeLatencyInfo(&frame->metadata.latency_info);
+  }
+
   // TODO(jamesr): Aggregate all resource references into the returned frame's
   // resource list.