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

chrome/browser/browser_process_impl.cc

 // 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.
 
 #include "chrome/browser/browser_process_impl.h"
 
 #include <map>
 #include <set>
 #include <vector>
 
@@ skipping 306 matching lines @@
   did_start_ = true;
   module_ref_count_++;
   return module_ref_count_;
 }
 
 unsigned int BrowserProcessImpl::ReleaseModule() {
   DCHECK(CalledOnValidThread());
   DCHECK_NE(0u, module_ref_count_);
   module_ref_count_--;
   if (0 == module_ref_count_) {
+    CHECK(MessageLoop::current()->is_running());
     // Allow UI and IO threads to do blocking IO on shutdown, since we do a lot
     // of it on shutdown for valid reasons.
     base::ThreadRestrictions::SetIOAllowed(true);
     CHECK(!BrowserList::GetLastActive());
     io_thread()->message_loop()->PostTask(
         FROM_HERE,
         NewRunnableFunction(&base::ThreadRestrictions::SetIOAllowed, true));
 
 #if defined(OS_MACOSX)
     MessageLoop::current()->PostTask(
@@ skipping 819 matching lines @@
 }
 
 void BrowserProcessImpl::OnAutoupdateTimer() {
   if (CanAutorestartForUpdate()) {
     DLOG(WARNING) << "Detected update.  Restarting browser.";
     RestartPersistentInstance();
   }
 }
 
 #endif  // (defined(OS_WIN) || defined(OS_LINUX)) && !defined(OS_CHROMEOS)