Add latency measurement system

content/common/gpu/image_transport_surface_mac.cc

Index: content/common/gpu/image_transport_surface_mac.cc
diff --git a/content/common/gpu/image_transport_surface_mac.cc b/content/common/gpu/image_transport_surface_mac.cc
index 23a02ccf8157b67caa9e5734167801a8009eb4db..821e346c3088458c0e3f1bc88d45138c51582206 100644
--- a/content/common/gpu/image_transport_surface_mac.cc
+++ b/content/common/gpu/image_transport_surface_mac.cc
@@ -61,6 +61,7 @@ class IOSurfaceImageTransportSurface : public gfx::NoOpGLSurfaceCGL,
       const AcceleratedSurfaceMsg_BufferPresented_Params& params) OVERRIDE;
   virtual void OnResizeViewACK() OVERRIDE;
   virtual void OnResize(gfx::Size size) OVERRIDE;
+  virtual void SetLatencyInfo(const cc::LatencyInfo&) OVERRIDE;
 
  private:
   virtual ~IOSurfaceImageTransportSurface() OVERRIDE;
@@ -295,6 +296,11 @@ void IOSurfaceImageTransportSurface::OnResize(gfx::Size size) {
   CreateIOSurface();
 }
 
+void IOSurfaceImageTransportSurface::SetLatencyInfo(
+    const cc::LatencyInfo&) {
+  // TODO: implement
+}
+
 void IOSurfaceImageTransportSurface::UnrefIOSurface() {
   // If we have resources to destroy, then make sure that we have a current
   // context which we can use to delete the resources.