Move a bunch of child-only code from content/common to content/child

content/common/child_process.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 CONTENT_COMMON_CHILD_PROCESS_H_
-#define CONTENT_COMMON_CHILD_PROCESS_H_
-
-#include "base/basictypes.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/threading/thread.h"
-#include "base/synchronization/waitable_event.h"
-#include "content/common/content_export.h"
-
-namespace content {
-class ChildThread;
-
-// Base class for child processes of the browser process (i.e. renderer and
-// plugin host). This is a singleton object for each child process.
-class CONTENT_EXPORT ChildProcess {
- public:
-  // Child processes should have an object that derives from this class.
-  // Normally you would immediately call set_main_thread after construction.
-  ChildProcess();
-  virtual ~ChildProcess();
-
-  // May be NULL if the main thread hasn't been set explicitly.
-  ChildThread* main_thread();
-
-  // Sets the object associated with the main thread of this process.
-  // Takes ownership of the pointer.
-  void set_main_thread(ChildThread* thread);
-
-  base::MessageLoop* io_message_loop() { return io_thread_.message_loop(); }
-  base::MessageLoopProxy* io_message_loop_proxy() {
-    return io_thread_.message_loop_proxy();
-  }
-
-  // A global event object that is signalled when the main thread's message
-  // loop exits.  This gives background threads a way to observe the main
-  // thread shutting down.  This can be useful when a background thread is
-  // waiting for some information from the browser process.  If the browser
-  // process goes away prematurely, the background thread can at least notice
-  // the child processes's main thread exiting to determine that it should give
-  // up waiting.
-  // For example, see the renderer code used to implement
-  // webkit_glue::GetCookies.
-  base::WaitableEvent* GetShutDownEvent();
-
-  // These are used for ref-counting the child process.  The process shuts
-  // itself down when the ref count reaches 0.
-  // For example, in the renderer process, generally each tab managed by this
-  // process will hold a reference to the process, and release when closed.
-  void AddRefProcess();
-  void ReleaseProcess();
-
-  // Getter for the one ChildProcess object for this process.
-  static ChildProcess* current();
-
-  static void WaitForDebugger(const std::string& label);
- private:
-  int ref_count_;
-
-  // An event that will be signalled when we shutdown.
-  base::WaitableEvent shutdown_event_;
-
-  // The thread that handles IO events.
-  base::Thread io_thread_;
-
-  // NOTE: make sure that main_thread_ is listed after shutdown_event_, since
-  // it depends on it (indirectly through IPC::SyncChannel).  Same for
-  // io_thread_.
-  scoped_ptr<ChildThread> main_thread_;
-
-  DISALLOW_COPY_AND_ASSIGN(ChildProcess);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_COMMON_CHILD_PROCESS_H_