Make --enable-delegated-renderer show stuff on Mac

content/browser/renderer_host/render_widget_helper.h

Index: content/browser/renderer_host/render_widget_helper.h
diff --git a/content/browser/renderer_host/render_widget_helper.h b/content/browser/renderer_host/render_widget_helper.h
index 50ecdbda4912bb05f61024cadb0e5365543cfcca..1a008f7ef3083a3d93ff10e16a8047ef07705fb6 100644
--- a/content/browser/renderer_host/render_widget_helper.h
+++ b/content/browser/renderer_host/render_widget_helper.h
@@ -30,6 +30,7 @@ namespace base {
 class TimeDelta;
 }
 
+struct GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params;
 struct ViewHostMsg_CreateWindow_Params;
 struct ViewMsg_SwapOut_Params;
 
@@ -167,6 +168,11 @@ class RenderWidgetHelper
   void FreeTransportDIB(TransportDIB::Id dib_id);
 #endif
 
+#if defined(OS_MACOSX)
+  static void OnNativeSurfaceBuffersSwapped(
+      const GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params& params);
+#endif
+
  private:
   // A class used to proxy a paint message.  PaintMsgProxy objects are created
   // on the IO thread and destroyed on the UI thread.