Delete background tab IOSurfaces on Mac.

content/browser/renderer_host/render_message_filter.cc

Index: content/browser/renderer_host/render_message_filter.cc
diff --git a/content/browser/renderer_host/render_message_filter.cc b/content/browser/renderer_host/render_message_filter.cc
index 0976394c403c66afeea48beff8a817243d385aba..879c2e6cfa699de490e485884551295dde9102ce 100644
--- a/content/browser/renderer_host/render_message_filter.cc
+++ b/content/browser/renderer_host/render_message_filter.cc
@@ -361,7 +361,7 @@ bool RenderMessageFilter::OnMessageReceived(const IPC::Message& message,
     IPC_MESSAGE_HANDLER(ViewHostMsg_OpenChannelToPpapiBroker,
                         OnOpenChannelToPpapiBroker)
     IPC_MESSAGE_HANDLER_GENERIC(ViewHostMsg_UpdateRect,
-        render_widget_helper_->DidReceiveUpdateMsg(message))
+        render_widget_helper_->DidReceiveBackingStoreMsg(message))
     IPC_MESSAGE_HANDLER(ViewHostMsg_UpdateIsDelayed, OnUpdateIsDelayed)
     IPC_MESSAGE_HANDLER(DesktopNotificationHostMsg_CheckPermission,
                         OnCheckNotificationPermission)
@@ -948,5 +948,5 @@ void RenderMessageFilter::OnUpdateIsDelayed(const IPC::Message& msg) {
   // the renderer sent us this message, so that we can unblock the UI thread.
   // We will simply re-use the UpdateRect unblock mechanism, just with a
   // different message.
-  render_widget_helper_->DidReceiveUpdateMsg(msg);
+  render_widget_helper_->DidReceiveBackingStoreMsg(msg);
 }