Surface Synchronization: Distinguish between dependencies and references

cc/surfaces/surface_dependency_tracker.cc

Index: cc/surfaces/surface_dependency_tracker.cc
diff --git a/cc/surfaces/surface_dependency_tracker.cc b/cc/surfaces/surface_dependency_tracker.cc
index 9e059072223b3805029769c79d80e255e6156611..dbeafe4b6bd03a76d379ebe1ed603a8dfc7ed282 100644
--- a/cc/surfaces/surface_dependency_tracker.cc
+++ b/cc/surfaces/surface_dependency_tracker.cc
@@ -103,11 +103,6 @@ const BeginFrameArgs& SurfaceDependencyTracker::LastUsedBeginFrameArgs() const {
 
 void SurfaceDependencyTracker::OnBeginFrameSourcePausedChanged(bool paused) {}
 
-void SurfaceDependencyTracker::OnReferencedSurfacesChanged(
-    Surface* surface,
-    const std::vector<SurfaceId>* active_referenced_surfaces,
-    const std::vector<SurfaceId>* pending_referenced_surfaces) {}
-
 void SurfaceDependencyTracker::OnSurfaceDiscarded(Surface* surface) {
   // If the surface being destroyed doesn't have a pending frame then we have
   // nothing to do here.