IPC: Make ChannelReader inherit from SupportsAttachmentBrokering.

ipc/ipc_channel_reader.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 IPC_IPC_CHANNEL_READER_H_
 #define IPC_IPC_CHANNEL_READER_H_
 
 #include "base/basictypes.h"
+#include "ipc/attachment_broker.h"
 #include "ipc/ipc_channel.h"
 #include "ipc/ipc_export.h"
 
 namespace IPC {
 namespace internal {
 
 // This class provides common pipe reading functionality for the
 // platform-specific IPC channel implementations.
 //
 // It does the common input buffer management and message dispatch, while the
 // platform-specific parts provide the pipe management through a virtual
 // interface implemented on a per-platform basis.
 //
 // Note that there is no "writer" corresponding to this because the code for
 // writing to the channel is much simpler and has very little common
 // functionality that would benefit from being factored out. If we add
 // something like that in the future, it would be more appropriate to add it
 // here (and rename appropriately) rather than writing a different class.
-class ChannelReader {
+class ChannelReader : virtual public SupportsAttachmentBrokering {
  public:
   explicit ChannelReader(Listener* listener);
   virtual ~ChannelReader();
 
   void set_listener(Listener* listener) { listener_ = listener; }
 
   // Call to process messages received from the IPC connection and dispatch
   // them. Returns false on channel error. True indicates that everything
   // succeeded, although there may not have been any messages processed.
   bool ProcessIncomingMessages();
@@ skipping 63 matching lines @@
   // this buffer.
   std::string input_overflow_buf_;
 
   DISALLOW_COPY_AND_ASSIGN(ChannelReader);
 };
 
 }  // namespace internal
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_READER_H_