Replace --ppapi-keep-alive-throttle command line switch with IPC parameter.

ppapi/proxy/ppapi_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.
 
 // Multiply-included message header, no traditional include guard.
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 346 matching lines @@
   IPC_STRUCT_TRAITS_MEMBER(display_name)
   IPC_STRUCT_TRAITS_MEMBER(mtu)
 IPC_STRUCT_TRAITS_END()
 
 // Only whitelisted switches passed through PpapiNaClPluginArgs.
 // The list of switches can be found in:
 //   components/nacl/browser/nacl_process_host.cc
 IPC_STRUCT_TRAITS_BEGIN(ppapi::PpapiNaClPluginArgs)
   IPC_STRUCT_TRAITS_MEMBER(off_the_record)
   IPC_STRUCT_TRAITS_MEMBER(permissions)
+  IPC_STRUCT_TRAITS_MEMBER(keepalive_throttle_interval_milliseconds)
   IPC_STRUCT_TRAITS_MEMBER(switch_names)
   IPC_STRUCT_TRAITS_MEMBER(switch_values)
 IPC_STRUCT_TRAITS_END()
 
 #if !defined(OS_NACL) && !defined(NACL_WIN64)
 
 IPC_STRUCT_TRAITS_BEGIN(ppapi::proxy::PPPDecryptor_Buffer)
   IPC_STRUCT_TRAITS_MEMBER(resource)
   IPC_STRUCT_TRAITS_MEMBER(handle)
   IPC_STRUCT_TRAITS_MEMBER(size)
@@ skipping 1706 matching lines @@
 IPC_MESSAGE_CONTROL1(PpapiHostMsg_Talk_RequestPermission,
                      PP_TalkPermission /* permission */)
 IPC_MESSAGE_CONTROL0(PpapiPluginMsg_Talk_RequestPermissionReply)
 IPC_MESSAGE_CONTROL0(PpapiHostMsg_Talk_StartRemoting)
 IPC_MESSAGE_CONTROL0(PpapiPluginMsg_Talk_StartRemotingReply)
 IPC_MESSAGE_CONTROL0(PpapiHostMsg_Talk_StopRemoting)
 IPC_MESSAGE_CONTROL0(PpapiPluginMsg_Talk_StopRemotingReply)
 IPC_MESSAGE_CONTROL1(PpapiPluginMsg_Talk_NotifyEvent, PP_TalkEvent /* event */)
 
 #endif  // !defined(OS_NACL) && !defined(NACL_WIN64)