diff -r 000000000000 -r 6474c204b198 ipc/chromium/src/chrome/common/child_thread.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ipc/chromium/src/chrome/common/child_thread.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,88 @@
+// Copyright (c) 2009 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 CHROME_COMMON_CHILD_THREAD_H_
+#define CHROME_COMMON_CHILD_THREAD_H_
+
+#include "base/thread.h"
+#include "chrome/common/ipc_sync_channel.h"
+#include "chrome/common/message_router.h"
+
+class ResourceDispatcher;
+
+// Child processes's background thread should derive from this class.
+class ChildThread : public IPC::Channel::Listener,
+                    public IPC::Message::Sender,
+                    public base::Thread {
+ public:
+  // Creates the thread.
+  ChildThread(Thread::Options options);
+  virtual ~ChildThread();
+
+  // IPC::Message::Sender implementation:
+  virtual bool Send(IPC::Message* msg);
+
+  // See documentation on MessageRouter for AddRoute and RemoveRoute
+  void AddRoute(int32_t routing_id, IPC::Channel::Listener* listener);
+  void RemoveRoute(int32_t routing_id);
+
+  MessageLoop* owner_loop() { return owner_loop_; }
+
+ protected:
+  friend class ChildProcess;
+
+  // Starts the thread.
+  bool Run();
+
+  // Overrides the channel name.  Used for --single-process mode.
+  void SetChannelName(const std::wstring& name) { channel_name_ = name; }
+
+  // Called when the process refcount is 0.
+  void OnProcessFinalRelease();
+
+ protected:
+  // The required stack size if V8 runs on a thread.
+  static const size_t kV8StackSize;
+
+  virtual void OnControlMessageReceived(const IPC::Message& msg) { }
+
+  // Returns the one child thread.
+  static ChildThread* current();
+
+  IPC::Channel* channel() { return channel_.get(); }
+
+  // Thread implementation.
+  virtual void Init();
+  virtual void CleanUp();
+
+ private:
+  // IPC::Channel::Listener implementation:
+  virtual void OnMessageReceived(const IPC::Message& msg);
+  virtual void OnChannelError();
+
+#ifdef MOZ_NUWA_PROCESS
+  static void MarkThread();
+#endif
+
+  // The message loop used to run tasks on the thread that started this thread.
+  MessageLoop* owner_loop_;
+
+  std::wstring channel_name_;
+  scoped_ptr<IPC::Channel> channel_;
+
+  // Used only on the background render thread to implement message routing
+  // functionality to the consumers of the ChildThread.
+  MessageRouter router_;
+
+  Thread::Options options_;
+
+  // If true, checks with the browser process before shutdown.  This avoids race
+  // conditions if the process refcount is 0 but there's an IPC message inflight
+  // that would addref it.
+  bool check_with_browser_before_shutdown_;
+
+  DISALLOW_EVIL_CONSTRUCTORS(ChildThread);
+};
+
+#endif  // CHROME_COMMON_CHILD_THREAD_H_