Add latency measurement system

cc/thread_proxy.cc

Index: cc/thread_proxy.cc
diff --git a/cc/thread_proxy.cc b/cc/thread_proxy.cc
index cd0baa3b6aa6dbc3d892f62a2f039722001599bb..a1042d1ab2874106d7d46f2062443044793e3438 100644
--- a/cc/thread_proxy.cc
+++ b/cc/thread_proxy.cc
@@ -846,6 +846,20 @@ void ThreadProxy::didCommitAndDrawFrame()
     m_layerTreeHost->didCommitAndDrawFrame();
 }
 
+void ThreadProxy::onReceivedLatencyInfo(const WebKit::WebLatencyInfoImpl& latencyInfo)
+{
+    DCHECK(isImplThread());
+    m_mainThreadProxy->postTask(FROM_HERE, base::Bind(&ThreadProxy::receivedLatencyInfo, base::Unretained(this), latencyInfo));
+}
+
+void ThreadProxy::receivedLatencyInfo(const WebKit::WebLatencyInfoImpl& latencyInfo)
+{
+    DCHECK(isMainThread());
+    if (!m_layerTreeHost)
+        return;
+    m_layerTreeHost->onReceivedLatencyInfo(latencyInfo);
+}
+
 void ThreadProxy::didCompleteSwapBuffers()
 {
     DCHECK(isMainThread());