Send vsync timebase updates to the browser compositor

content/common/gpu/gpu_messages.h

Index: content/common/gpu/gpu_messages.h
diff --git a/content/common/gpu/gpu_messages.h b/content/common/gpu/gpu_messages.h
index 4549e305262c5aee9a38aac71ba2494da8c86b30..48219f516a19b81fd0e5f9b02f88e202ac6119df 100644
--- a/content/common/gpu/gpu_messages.h
+++ b/content/common/gpu/gpu_messages.h
@@ -377,6 +377,11 @@ IPC_MESSAGE_CONTROL1(GpuHostMsg_AcceleratedSurfaceRelease,
 IPC_MESSAGE_CONTROL1(GpuHostMsg_AcceleratedSurfaceSuspend,
                      int32 /* surface_id */)
 
+// Tells the browser about updated parameters for vsync alignment.
+IPC_MESSAGE_CONTROL2(GpuHostMsg_UpdateVSyncParameters,

[piman, 2012/10/24 16:56:54]

Something is missing here, when you have multiple screens (multiple GLSurfaces,
multiple refresh rate/alignment).
You need an identifier to associate this data to the right surface.

[ajuma, 2012/10/26 20:12:39]

Done.

+                     base::TimeTicks /* timebase */,
+                     base::TimeDelta /* interval */)
+
 //------------------------------------------------------------------------------
 // GPU Channel Messages
 // These are messages from a renderer process to the GPU process.