Add a new pair of IPC categories for messages that need handling as input events

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,
   ViewMsgStart,
+  InputMsgStart,
   PluginMsgStart,
   ProfileImportMsgStart,
   TestMsgStart,
   DevToolsMsgStart,
   WorkerMsgStart,
   NaClMsgStart,
   UtilityMsgStart,
   GpuMsgStart,
   ServiceMsgStart,
   PpapiMsgStart,
@@ skipping 50 matching lines @@
   TracingMsgStart,
   PeerConnectionTrackerMsgStart,
   VisitedLinkMsgStart,
   OneClickSigninMsgStart,
   AppShimMsgStart,
   WebRtcLoggingMsgStart,
   LastIPCMsgStart      // Must come last.
 };
 
 #endif  // IPC_IPC_MESSAGE_START_H_