Add latency measurement system

cc/renderer.h

Index: cc/renderer.h
diff --git a/cc/renderer.h b/cc/renderer.h
index 981679cc08826f942e6e2a17d8ba421f9a64aaf1..84776e40e60e6f4163dc81d15d5c47176536c529 100644
--- a/cc/renderer.h
+++ b/cc/renderer.h
@@ -26,6 +26,7 @@ public:
     virtual void setManagedMemoryPolicy(const ManagedMemoryPolicy& policy) = 0;
     virtual void enforceManagedMemoryPolicy(const ManagedMemoryPolicy& policy) = 0;
     virtual bool hasImplThread() const = 0;
+    virtual void onReceivedLatencyInfo(const WebKit::WebLatencyInfoImpl&) = 0;
 protected:
     virtual ~RendererClient() { }
 };
@@ -72,6 +73,8 @@ public:
 
     virtual void setVisible(bool) = 0;
 
+    virtual void setLatencyInfo(const WebKit::WebLatencyInfoImpl&) = 0;
+
     virtual void sendManagedMemoryStats(size_t bytesVisible, size_t bytesVisibleAndNearby, size_t bytesAllocated) = 0;
 
 protected: