Provide a vsync notification to the renderer

content/common/view_messages.h

Index: content/common/view_messages.h
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index 75ece081b1bea68e3b672e1d6e2d802876b48748..c04f1ac5b7e1a520a3ca713d7a650cf4ee87e839 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -1643,11 +1643,22 @@ IPC_MESSAGE_ROUTED1(ViewHostMsg_UpdateRect,
 // which may get delayed until the browser's UI unblocks.
 IPC_MESSAGE_ROUTED0(ViewHostMsg_UpdateIsDelayed)
 
-// Sent by the renderer when the parameters for vsync alignment have changed.
+// Sent by the browser when the parameters for vsync alignment have changed.
 IPC_MESSAGE_ROUTED2(ViewMsg_UpdateVSyncParameters,
                     base::TimeTicks /* timebase */,
                     base::TimeDelta /* interval */)
 
+// Sent by renderer to request a ViewMsg_VSync message for upcoming display
+// vsync events. If |enabled| is true, the vsync message will continue to be be
+// delivered until the notification is disabled.
+IPC_MESSAGE_ROUTED1(ViewHostMsg_EnableVSyncNotification,
+                    bool /* enabled */)
+
+// Sent by the browser when the display vsync signal was triggered and the
+// renderer should generate a new frame.
+IPC_MESSAGE_ROUTED1(ViewMsg_DidVSync,
+                    base::TimeTicks /* frame_time */)
+
 // Sent by the renderer when accelerated compositing is enabled or disabled to
 // notify the browser whether or not is should do painting.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_DidActivateAcceleratedCompositing,