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

ipc/ipc_sync_channel.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_SENDER_H__
-#define IPC_IPC_SYNC_SENDER_H__
+#ifndef IPC_IPC_SYNC_CHANNEL_H_
+#define IPC_IPC_SYNC_CHANNEL_H_
 #pragma once
 
 #include <string>
 #include <deque>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "base/synchronization/waitable_event_watcher.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_channel_proxy.h"
 #include "ipc/ipc_sync_message.h"
 
 namespace base {
 class WaitableEvent;
 };
 
 namespace IPC {
 
 class SyncMessage;
-class MessageReplyDeserializer;
 
 // This is similar to ChannelProxy, with the added feature of supporting sending
 // synchronous messages.
 //
 // Overview of how the sync channel works
 // --------------------------------------
 // When the sending thread sends a synchronous message, we create a bunch
 // of tracking info (created in SendWithTimeout, stored in the PendingSyncMsg
 // structure) associated with the message that we identify by the unique
 // "MessageId" on the SyncMessage. Among the things we save is the
@@ skipping 152 matching lines @@
   bool sync_messages_with_no_timeout_allowed_;
 
   // Used to signal events between the IPC and listener threads.
   base::WaitableEventWatcher dispatch_watcher_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncChannel);
 };
 
 }  // namespace IPC
 
-#endif  // IPC_IPC_SYNC_SENDER_H__
+#endif  // IPC_IPC_SYNC_CHANNEL_H_