Add CHECK to catch places where BrowserProcessImpl's refcount goes to 0.

base/message_loop.h

 // Copyright (c) 2011 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 BASE_MESSAGE_LOOP_H_
 #define BASE_MESSAGE_LOOP_H_
 #pragma once
 
 #include <queue>
 #include <string>
@@ skipping 359 matching lines @@
 #if defined(OS_WIN)
   void set_os_modal_loop(bool os_modal_loop) {
     os_modal_loop_ = os_modal_loop;
   }
 
   bool os_modal_loop() const {
     return os_modal_loop_;
   }
 #endif  // OS_WIN
 
+  // Can only be called from the thread that owns the MessageLoop.
+  bool is_running() const;
+
   //----------------------------------------------------------------------------
  protected:
   struct RunState {
     // Used to count how many Run() invocations are on the stack.
     int run_depth;
 
     // Used to record that Quit() was called, or that we should quit the pump
     // once it becomes idle.
     bool quit_received;
 
@@ skipping 321 matching lines @@
 #endif  // defined(OS_POSIX)
 };
 
 // Do not add any member variables to MessageLoopForIO!  This is important b/c
 // MessageLoopForIO is often allocated via MessageLoop(TYPE_IO).  Any extra
 // data that you need should be stored on the MessageLoop's pump_ instance.
 COMPILE_ASSERT(sizeof(MessageLoop) == sizeof(MessageLoopForIO),
                MessageLoopForIO_should_not_have_extra_member_variables);
 
 #endif  // BASE_MESSAGE_LOOP_H_