Revert of Reland #2 "ipc: Add a new field num_brokered_attachments to the message header."

ipc/ipc_channel.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_H_
 #define IPC_IPC_CHANNEL_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 151 matching lines @@
   // TODO(erikchen): Remove default parameter for |broker|. It exists only to
   // make the upcoming refactor decomposable into smaller CLs.
   // http://crbug.com/493414.
   static scoped_ptr<Channel> CreateServer(
       const IPC::ChannelHandle& channel_handle,
       Listener* listener,
       AttachmentBroker* broker = nullptr);
 
   ~Channel() override;
 
-  // TODO(erikchen): Temporary code to help track http://crbug.com/527588.
-  using MessageVerifier = void (*)(const Message*);
-  static void SetMessageVerifier(MessageVerifier verifier);
-  static MessageVerifier GetMessageVerifier();
-
   // Connect the pipe.  On the server side, this will initiate
   // waiting for connections.  On the client, it attempts to
   // connect to a pre-existing pipe.  Note, calling Connect()
   // will not block the calling thread and may complete
   // asynchronously.
   virtual bool Connect() WARN_UNUSED_RESULT = 0;
 
   // Close this Channel explicitly.  May be called multiple times.
   // On POSIX calling close on an IPC channel that listens for connections will
   // cause it to close any accepted connections, and it will stop listening for
@@ skipping 85 matching lines @@
 
 #if defined(OS_POSIX)
 // SocketPair() creates a pair of socket FDs suitable for using with
 // IPC::Channel.
 IPC_EXPORT bool SocketPair(int* fd1, int* fd2);
 #endif
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_H_