Deliver IPC messages together with SwapCompositorFrame

content/common/view_messages.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/memory/shared_memory.h"
 #include "base/process/process.h"
 #include "base/strings/string16.h"
@@ skipping 1484 matching lines @@
   IPC_STRUCT_MEMBER(std::vector<ui::LatencyInfo>, latency_info)
 IPC_STRUCT_END()
 
 // This message is synthesized by GpuProcessHost to pass through a swap message
 // to the RenderWidgetHelper. This allows GetBackingStore to block for either a
 // software or GPU frame.
 IPC_MESSAGE_ROUTED1(
     ViewHostMsg_CompositorSurfaceBuffersSwapped,
     ViewHostMsg_CompositorSurfaceBuffersSwapped_Params /* params */)
 
-IPC_MESSAGE_ROUTED2(ViewHostMsg_SwapCompositorFrame,
-                    uint32 /* output_surface_id */,
-                    cc::CompositorFrame /* frame */)
+IPC_MESSAGE_ROUTED3(
+    ViewHostMsg_SwapCompositorFrame,
+    uint32 /* output_surface_id */,
+    cc::CompositorFrame /* frame */,
+    std::vector<IPC::Message> /* messages_to_deliver_with_frame */)
 
 // Sent by the compositor when input scroll events are dropped due to bounds
 // restricions on the root scroll offset.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_DidOverscroll,
                     content::DidOverscrollParams /* params */)
 
 // Sent by the compositor when a flinging animation is stopped.
 IPC_MESSAGE_ROUTED0(ViewHostMsg_DidStopFlinging)
 
 //---------------------------------------------------------------------------
@@ skipping 244 matching lines @@
 // synchronously (see crbug.com/120597). This IPC message sends the character
 // bounds after every composition change to always have correct bound info.
 IPC_MESSAGE_ROUTED2(ViewHostMsg_ImeCompositionRangeChanged,
                     gfx::Range /* composition range */,
                     std::vector<gfx::Rect> /* character bounds */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent ViewMsg, then ifdefs for platform specific ViewMsg, then platform
 // independent ViewHostMsg, then ifdefs for platform specific ViewHostMsg.