Update ChannelReader to use AttachmentBroker.

ipc/ipc_message.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_MESSAGE_H_
 #define IPC_IPC_MESSAGE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/pickle.h"
 #include "base/trace_event/trace_event.h"
 #include "ipc/ipc_export.h"
 
 #if !defined(NDEBUG)
 #define IPC_MESSAGE_LOG_ENABLED
 #endif
 
 namespace IPC {
 
+namespace internal {
+class ChannelReader;
+}  // namespace internal
+
 //------------------------------------------------------------------------------
 
 struct LogData;
 class MessageAttachment;
 class MessageAttachmentSet;
 
 class IPC_EXPORT Message : public base::Pickle {
  public:
   enum PriorityValue {
     PRIORITY_LOW = 1,
@@ skipping 178 matching lines @@
     TRACE_EVENT_FLOW_END_BIND_TO_ENCLOSING0(
         TRACE_DISABLED_BY_DEFAULT("ipc.flow"), "IPC", header()->flags);
   }
 
  protected:
   friend class Channel;
   friend class ChannelMojo;
   friend class ChannelNacl;
   friend class ChannelPosix;
   friend class ChannelWin;
+  friend class internal::ChannelReader;
   friend class MessageReplyDeserializer;
   friend class SyncMessage;
 
 #pragma pack(push, 4)
   struct Header : base::Pickle::Header {
     int32 routing;  // ID of the view that this message is destined for
     uint32 type;    // specifies the user-defined message type
     uint32 flags;   // specifies control flags for the message
 #if defined(OS_POSIX)
     uint16 num_fds; // the number of descriptors included with this message
@@ skipping 46 matching lines @@
   MSG_ROUTING_NONE = -2,
 
   // indicates a general message not sent to a particular tab.
   MSG_ROUTING_CONTROL = kint32max,
 };
 
 #define IPC_REPLY_ID 0xFFFFFFF0  // Special message id for replies
 #define IPC_LOGGING_ID 0xFFFFFFF1  // Special message id for logging
 
 #endif  // IPC_IPC_MESSAGE_H_