Send vsync timebase updates to the browser compositor

cc/gl_renderer.cc

Index: cc/gl_renderer.cc
diff --git a/cc/gl_renderer.cc b/cc/gl_renderer.cc
index f5736071cdf739a0247397b7c87359da6f7f4a98..4c439bc4b4ca27b048ce926ba68701d805d75b3b 100644
--- a/cc/gl_renderer.cc
+++ b/cc/gl_renderer.cc
@@ -107,8 +107,10 @@ bool CCRendererGL::initialize()
     m_capabilities.usingPartialSwap = CCSettings::partialSwapEnabled() && extensions.count("GL_CHROMIUM_post_sub_buffer");
 
     // Use the swapBuffers callback only with the threaded proxy.
-    if (CCProxy::hasImplThread())
+    if (CCProxy::hasImplThread()) {
         m_capabilities.usingSwapCompleteCallback = extensions.count("GL_CHROMIUM_swapbuffers_complete_callback");
+        m_context->setUpdateVSyncTimeCallbackCHROMIUM(this);
+    }
     if (m_capabilities.usingSwapCompleteCallback)
         m_context->setSwapBuffersCompleteCallbackCHROMIUM(this);
 
@@ -1109,6 +1111,11 @@ void CCRendererGL::ensureFramebuffer()
     m_isFramebufferDiscarded = false;
 }
 
+void CCRendererGL::onUpdateVSyncTime(int64 time)
+{
+    m_client->onUpdateVSyncTime(time);
+}
+
 void CCRendererGL::onContextLost()
 {
     m_client->didLoseContext();