Support distributing vsync info with surfaces.

cc/surfaces/display_client.h

Index: cc/surfaces/display_client.h
diff --git a/cc/surfaces/display_client.h b/cc/surfaces/display_client.h
index 0c5f3ccfa05a0cb8af02b7a5b35846ef81096854..2c8988339539cc253ab607bf1d0ce5bce90953e1 100644
--- a/cc/surfaces/display_client.h
+++ b/cc/surfaces/display_client.h
@@ -6,6 +6,7 @@
 #define CC_SURFACES_DISPLAY_CLIENT_H_
 
 #include "base/memory/scoped_ptr.h"
+#include "base/time/time.h"
 
 namespace cc {
 
@@ -17,6 +18,8 @@ class DisplayClient {
   virtual void DisplayDamaged() = 0;
   virtual void DidSwapBuffers() = 0;
   virtual void DidSwapBuffersComplete() = 0;
+  virtual void CommitVSyncParameters(base::TimeTicks timebase,
+                                     base::TimeDelta interval) = 0;
 
  protected:
   virtual ~DisplayClient() {}