Add support for MojoChannel field trial

ipc/mojo/ipc_channel_mojo.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 IPC_IPC_CHANNEL_MOJO_H_
 #define IPC_IPC_CHANNEL_MOJO_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 20 matching lines @@
 // channel.
 //
 // TODO(morrita): Add APIs to create extra MessagePipes to let
 //                Mojo-based objects talk over this Channel.
 //
 class IPC_MOJO_EXPORT ChannelMojo
     : public Channel,
       public MojoBootstrap::Delegate,
       public NON_EXPORTED_BASE(internal::MessagePipeReader::Delegate) {
  public:
-  // True if ChannelMojo should be used regardless of the flag.
-  static bool ShouldBeUsed();
-
   // Creates a ChannelMojo.
   static scoped_ptr<ChannelMojo> Create(mojo::ScopedMessagePipeHandle handle,
                                         Mode mode,
                                         Listener* listener);
 
   // Create a factory object for ChannelMojo.
   // The factory is used to create Mojo-based ChannelProxy family.
   // |host| must not be null.
   static scoped_ptr<ChannelFactory> CreateServerFactory(
       mojo::ScopedMessagePipeHandle handle);
@@ skipping 57 matching lines @@
   bool waiting_connect_;
 
   base::WeakPtrFactory<ChannelMojo> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ChannelMojo);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_MOJO_H_