Thread::Stop() must be called before any subclass's destructor completes.

chrome/browser/metrics/thread_watcher.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/metrics/thread_watcher.h"
 
 #include <math.h>  // ceil
 
 #include "base/bind.h"
 #include "base/debug/alias.h"
@@ skipping 612 matching lines @@
 WatchDogThread* WatchDogThread::watchdog_thread_ = NULL;
 
 // The WatchDogThread object must outlive any tasks posted to the IO thread
 // before the Quit task.
 DISABLE_RUNNABLE_METHOD_REFCOUNT(WatchDogThread);
 
 WatchDogThread::WatchDogThread() : Thread("BrowserWatchdog") {
 }
 
 WatchDogThread::~WatchDogThread() {
-  // We cannot rely on our base class to stop the thread since we want our
-  // CleanUp function to run.
   Stop();
 }
 
 // static
 bool WatchDogThread::CurrentlyOnWatchDogThread() {
   base::AutoLock lock(lock_);
   return watchdog_thread_ &&
     watchdog_thread_->message_loop() == MessageLoop::current();
 }
 
@@ skipping 146 matching lines @@
 
 #if defined(OS_WIN)
   // On Windows XP, give twice the time for shutdown.
   if (base::win::GetVersion() <= base::win::VERSION_XP)
     actual_duration *= 2;
 #endif
 
   shutdown_watchdog_ = new ShutdownWatchDogThread(actual_duration);
   shutdown_watchdog_->Arm();
 }