extensions: Cleanup class/struct fwd declarations

extensions/browser/api/cast_channel/cast_transport.h

 // Copyright 2014 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 EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_TRANSPORT_H_
 #define EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_TRANSPORT_H_
 
 #include <queue>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/threading/thread_checker.h"
 #include "extensions/browser/api/cast_channel/logger.h"
 #include "extensions/common/api/cast_channel.h"
 #include "extensions/common/api/cast_channel/logging.pb.h"
 #include "net/base/completion_callback.h"
 
 namespace net {
 class DrainableIOBuffer;
 class IPEndPoint;
-class IOBuffer;
 class DrainableIOBuffer;
 class GrowableIOBuffer;
 class Socket;
 }  // namespace net
 
 namespace extensions {
 namespace api {
 namespace cast_channel {
 class CastMessage;
-struct LastErrors;
 class Logger;
 class MessageFramer;
 
 class CastTransport {
  public:
   virtual ~CastTransport() {}
 
   // Object to be informed of incoming messages and read errors.
   class Delegate {
    public:
@@ skipping 174 matching lines @@
   // Accumulates details of events and errors, for debugging purposes.
   scoped_refptr<Logger> logger_;
 
   DISALLOW_COPY_AND_ASSIGN(CastTransportImpl);
 };
 }  // namespace cast_channel
 }  // namespace api
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_TRANSPORT_H_