Add latency measurement system

content/browser/renderer_host/image_transport_factory.cc

Index: content/browser/renderer_host/image_transport_factory.cc
diff --git a/content/browser/renderer_host/image_transport_factory.cc b/content/browser/renderer_host/image_transport_factory.cc
index a2fce40d2f2caa2a86417ba1127ca2807324b361..c4c3a34a52d5ce0339f1b255f832d15d994688bb 100644
--- a/content/browser/renderer_host/image_transport_factory.cc
+++ b/content/browser/renderer_host/image_transport_factory.cc
@@ -321,6 +321,9 @@ class BrowserCompositorOutputSurface :
 
     client_ = client;
     output_surface_proxy_->AddSurface(this, surface_id_);
+    context3D_->GetCommandBufferProxy()->SetLatencyInfoCallback(
+        base::Bind(&BrowserCompositorOutputSurface::OnReceivedLatencyInfo,
+                   base::Unretained(this)));
     return true;
   }
 
@@ -343,6 +346,11 @@ class BrowserCompositorOutputSurface :
       const cc::CompositorFrame&) OVERRIDE {
   }
 
+  virtual void SetLatencyInfo(
+      const cc::LatencyInfo& latency_info) OVERRIDE {
+    context3D_->GetCommandBufferProxy()->SetLatencyInfo(latency_info);
+  }
+
   void OnUpdateVSyncParameters(
       base::TimeTicks timebase, base::TimeDelta interval) {
     DCHECK(CalledOnValidThread());
@@ -351,6 +359,11 @@ class BrowserCompositorOutputSurface :
   }
 
  private:
+
+  void OnReceivedLatencyInfo(const cc::LatencyInfo& latency_info) {
+    client_->OnReceivedLatencyInfo(latency_info);
+  }
+
   scoped_ptr<WebGraphicsContext3DCommandBufferImpl> context3D_;
   int surface_id_;
   struct Capabilities capabilities_;