cc: Dedup IPCs to return resources to client

cc/ipc/cc_param_traits.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 sent between compositor instances.
 
 #ifndef CC_IPC_CC_PARAM_TRAITS_H_
 #define CC_IPC_CC_PARAM_TRAITS_H_
 
 #include "cc/ipc/cc_ipc_export.h"
 #include "cc/ipc/cc_param_traits_macros.h"
 #include "cc/output/compositor_frame.h"
-#include "cc/output/compositor_frame_ack.h"
 #include "cc/output/filter_operation.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/quads/stream_video_draw_quad.h"
 #include "cc/quads/texture_draw_quad.h"
 #include "gpu/ipc/common/gpu_command_buffer_traits.h"
 #include "ipc/ipc_message_macros.h"
 
 namespace gfx {
 class Transform;
 }
@@ skipping 62 matching lines @@
 struct CC_IPC_EXPORT ParamTraits<cc::CompositorFrame> {
   typedef cc::CompositorFrame param_type;
   static void Write(base::Pickle* m, const param_type& p);
   static bool Read(const base::Pickle* m,
                    base::PickleIterator* iter,
                    param_type* p);
   static void Log(const param_type& p, std::string* l);
 };
 
 template <>
-struct CC_IPC_EXPORT ParamTraits<cc::CompositorFrameAck> {
-  typedef cc::CompositorFrameAck param_type;
-  static void Write(base::Pickle* m, const param_type& p);
-  static bool Read(const base::Pickle* m,
-                   base::PickleIterator* iter,
-                   param_type* p);
-  static void Log(const param_type& p, std::string* l);
-};
-
-template <>
 struct CC_IPC_EXPORT ParamTraits<cc::DelegatedFrameData> {
   typedef cc::DelegatedFrameData param_type;
   static void Write(base::Pickle* m, const param_type& p);
   static bool Read(const base::Pickle* m,
                    base::PickleIterator* iter,
                    param_type* p);
   static void Log(const param_type& p, std::string* l);
 };
 
 template <>
@@ skipping 25 matching lines @@
   static void Write(base::Pickle* m, const param_type& p);
   static bool Read(const base::Pickle* m,
                    base::PickleIterator* iter,
                    param_type* p);
   static void Log(const param_type& p, std::string* l);
 };
 
 }  // namespace IPC
 
 #endif  // CC_IPC_CC_PARAM_TRAITS_H_