Cleanup: Remove unneeded forward declarations in base, dbug, gpu, ipc, jingle, and media.

ipc/ipc_sync_message_filter.h

 // Copyright (c) 2011 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_SYNC_MESSAGE_FILTER_H_
 #define IPC_IPC_SYNC_MESSAGE_FILTER_H_
 #pragma once
 
+#include <set>
+
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "ipc/ipc_channel_proxy.h"
 #include "ipc/ipc_sync_message.h"
-#include <set>
 
 namespace base {
 class MessageLoopProxy;
 class WaitableEvent;
 }
 
 namespace IPC {
 
-class MessageReplyDeserializer;
-
 // This MessageFilter allows sending synchronous IPC messages from a thread
 // other than the listener thread associated with the SyncChannel.  It does not
 // support fancy features that SyncChannel does, such as handling recursion or
 // receiving messages while waiting for a response.  Note that this object can
 // be used to send simultaneous synchronous messages from different threads.
 class IPC_EXPORT SyncMessageFilter : public ChannelProxy::MessageFilter,
                                      public Message::Sender {
  public:
   explicit SyncMessageFilter(base::WaitableEvent* shutdown_event);
   virtual ~SyncMessageFilter();
@@ skipping 28 matching lines @@
   base::Lock lock_;
 
   base::WaitableEvent* shutdown_event_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncMessageFilter);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_SYNC_MESSAGE_FILTER_H_