Decouple GpuCompositorFrameSink from DisplayCompositor

cc/surfaces/surface_reference_manager.h

Index: cc/surfaces/surface_reference_manager.h
diff --git a/cc/surfaces/surface_reference_manager.h b/cc/surfaces/surface_reference_manager.h
index 66d55c67a4e96f703ed131bd4341537b90802808..7eec022f9d5c54437f885c31751b1a98da7f9153 100644
--- a/cc/surfaces/surface_reference_manager.h
+++ b/cc/surfaces/surface_reference_manager.h
@@ -5,6 +5,8 @@
 #ifndef CC_SURFACES_SURFACE_REFERENCE_MANAGER_H_
 #define CC_SURFACES_SURFACE_REFERENCE_MANAGER_H_
 
+#include "cc/surfaces/surface_reference.h"
+
 namespace cc {
 
 class SurfaceId;
@@ -27,6 +29,15 @@ class SurfaceReferenceManager {
   virtual void RemoveSurfaceReference(const SurfaceId& parent_id,
                                       const SurfaceId& child_id) = 0;
 
+  // Adds surface references. For each reference added, this will remove the
+  // temporary reference to the child surface if one exists.
+  virtual void AddSurfaceReferences(
+      const std::vector<SurfaceReference>& references) = 0;
+
+  // Removes surface references.
+  virtual void RemoveSurfaceReferences(
+      const std::vector<SurfaceReference>& references) = 0;
+
   // Returns the number of surfaces that have references to |surface_id|. When
   // the count is zero nothing is referencing the surface and it may be garbage
   // collected.