Move Mojo channel initialization closer to IPC::Channel setup

mojo/common/mojo_channel_init.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 MOJO_COMMON_MOJO_CHANNEL_INIT_H_
-#define MOJO_COMMON_MOJO_CHANNEL_INIT_H_
-
-#include "base/memory/ref_counted.h"
-#include "base/memory/weak_ptr.h"
-#include "base/platform_file.h"
-#include "mojo/common/mojo_common_export.h"
-#include "mojo/public/cpp/system/core.h"
-
-namespace base {
-class MessageLoopProxy;
-class TaskRunner;
-}
-
-namespace mojo {
-namespace embedder {
-struct ChannelInfo;
-}
-
-namespace common {
-
-// MojoChannelInit handle creation (and destruction) of the mojo channel. It is
-// expected that this class is created and destroyed on the main thread.
-class MOJO_COMMON_EXPORT MojoChannelInit {
- public:
-  MojoChannelInit();
-  ~MojoChannelInit();
-
-  // Inits the channel. This takes ownership of |file|.
-  void Init(base::PlatformFile file,
-            scoped_refptr<base::TaskRunner> io_thread_task_runner);
-
-  bool is_handle_valid() const { return bootstrap_message_pipe_.is_valid(); }
-
-  mojo::ScopedMessagePipeHandle bootstrap_message_pipe() {
-    return bootstrap_message_pipe_.Pass();
-  }
-
- private:
-  // Invoked on the main thread once the channel has been established.
-  static void OnCreatedChannel(
-      base::WeakPtr<MojoChannelInit> host,
-      scoped_refptr<base::TaskRunner> io_thread,
-      embedder::ChannelInfo* channel);
-
-  scoped_refptr<base::TaskRunner> io_thread_task_runner_;
-
-  // If non-null the channel has been established.
-  embedder::ChannelInfo* channel_info_;
-
-  // The handle from channel creation.
-  mojo::ScopedMessagePipeHandle bootstrap_message_pipe_;
-
-  base::WeakPtrFactory<MojoChannelInit> weak_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(MojoChannelInit);
-};
-
-}  // namespace common
-}  // namespace mojo
-
-#endif  // MOJO_COMMON_MOJO_CHANNEL_INIT_H_