Surface Synchronization: Distinguish between dependencies and references

cc/surfaces/referenced_surface_tracker.cc

Index: cc/surfaces/referenced_surface_tracker.cc
diff --git a/cc/surfaces/referenced_surface_tracker.cc b/cc/surfaces/referenced_surface_tracker.cc
index ce1bf61c3fb6a46e54b7bdffbcd8e5a7561129ed..5e440d8828643ac7c1c561294b684bcb97ff1f22 100644
--- a/cc/surfaces/referenced_surface_tracker.cc
+++ b/cc/surfaces/referenced_surface_tracker.cc
@@ -20,8 +20,7 @@ ReferencedSurfaceTracker::~ReferencedSurfaceTracker() {}
 
 void ReferencedSurfaceTracker::UpdateReferences(
     const LocalSurfaceId& local_surface_id,
-    const std::vector<SurfaceId>* active_referenced_surfaces,
-    const std::vector<SurfaceId>* pending_referenced_surfaces) {
+    const std::vector<SurfaceId>* active_referenced_surfaces) {
   DCHECK(local_surface_id.is_valid());
 
   // Clear references to add/remove from the last frame.
@@ -43,11 +42,6 @@ void ReferencedSurfaceTracker::UpdateReferences(
                                   active_referenced_surfaces->end());
   }
 
-  if (pending_referenced_surfaces) {
-    referenced_surface_set.insert(pending_referenced_surfaces->begin(),
-                                  pending_referenced_surfaces->end());
-  }
-
   ProcessNewReferences(referenced_surface_set);
 }