Revert of Decouple browser-specific GPU IPC messages from GPU service IPCs

ipc/ipc_message_start.h

 // Copyright 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.
 
 #ifndef IPC_IPC_MESSAGE_START_H_
 #define IPC_IPC_MESSAGE_START_H_
 
 // Used by IPC_BEGIN_MESSAGES so that each message class starts from a unique
 // base.  Messages have unique IDs across channels in order for the IPC logging
 // code to figure out the message class from its ID.
 enum IPCMessageStart {
   AutomationMsgStart = 0,
   FrameMsgStart,
   ViewMsgStart,
   InputMsgStart,
   PluginMsgStart,
   PluginProcessMsgStart,
   ProfileImportMsgStart,
   TestMsgStart,
   DevToolsMsgStart,
   WorkerMsgStart,
   NaClMsgStart,
   UtilityMsgStart,
-  GpuChannelMsgStart,
   GpuMsgStart,
   ServiceMsgStart,
   PpapiMsgStart,
   FirefoxImporterUnittestMsgStart,
   FileUtilitiesMsgStart,
   MimeRegistryMsgStart,
   DatabaseMsgStart,
   DOMStorageMsgStart,
   IndexedDBMsgStart,
   SpeechRecognitionMsgStart,
@@ skipping 99 matching lines @@
   DistillerMsgStart,
   StartupMetricMsgStart,
   ArcCameraMsgStart,
   DWriteFontProxyMsgStart,
   MediaPlayerDelegateMsgStart,
   SurfaceViewManagerMsgStart,
   LastIPCMsgStart  // Must come last.
 };
 
 #endif  // IPC_IPC_MESSAGE_START_H_