net: Cleanup class/struct forward declarations

net/base/upload_data_stream.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.
 
 #ifndef NET_BASE_UPLOAD_DATA_STREAM_H_
 #define NET_BASE_UPLOAD_DATA_STREAM_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <vector>
 
 #include "base/macros.h"
 #include "net/base/completion_callback.h"
 #include "net/base/net_export.h"
 #include "net/base/upload_progress.h"
 #include "net/log/net_log_with_source.h"
 
 namespace net {
 
-class DrainableIOBuffer;
 class IOBuffer;
 class UploadElementReader;
 
 // A class for retrieving all data to be sent as a request body. Supports both
 // chunked and non-chunked uploads.
 class NET_EXPORT UploadDataStream {
  public:
   // |identifier| identifies a particular upload instance, which is used by the
   // cache to formulate a cache key. This value should be unique across browser
   // sessions. A value of 0 is used to indicate an unspecified identifier.
@@ skipping 111 matching lines @@
   CompletionCallback callback_;
 
   NetLogWithSource net_log_;
 
   DISALLOW_COPY_AND_ASSIGN(UploadDataStream);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_UPLOAD_DATA_STREAM_H_