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 ab708613204ecbc672900ca71bdb6abdef33994b..ace1eb3ac4f87cbc8e64897d4a11e4430d4ed5d2 100644
--- a/cc/thread_proxy.cc
+++ b/cc/thread_proxy.cc
@@ -867,6 +867,20 @@ void ThreadProxy::didCommitAndDrawFrame()
     m_layerTreeHost->didCommitAndDrawFrame();
 }
 
+void ThreadProxy::onReceivedLatencyInfo(const LatencyInfo& latencyInfo)
+{
+    DCHECK(isImplThread());
+    Proxy::mainThread()->postTask(base::Bind(&ThreadProxy::receivedLatencyInfo, base::Unretained(this), latencyInfo));
+}
+
+void ThreadProxy::receivedLatencyInfo(const LatencyInfo& latencyInfo)
+{
+    DCHECK(isMainThread());
+    if (!m_layerTreeHost)
+        return;
+    m_layerTreeHost->onReceivedLatencyInfo(latencyInfo);
+}
+
 void ThreadProxy::didCompleteSwapBuffers()
 {
     DCHECK(isMainThread());