Stop each ChromeThread before nulling out the entry in chrome_threads_. This...

chrome/browser/chrome_thread.cc

 // 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.
 
 #include "chrome/browser/chrome_thread.h"
 
 // Friendly names for the well-known threads.
 static const char* chrome_thread_names[ChromeThread::ID_COUNT] = {
   "",  // UI (name assembled in browser_main.cc).
   "Chrome_DBThread",  // DB
@@ skipping 23 matching lines @@
 }
 
 void ChromeThread::Initialize() {
   AutoLock lock(lock_);
   DCHECK(identifier_ >= 0 && identifier_ < ID_COUNT);
   DCHECK(chrome_threads_[identifier_] == NULL);
   chrome_threads_[identifier_] = this;
 }
 
 ChromeThread::~ChromeThread() {
+  // Stop the thread here, instead of the parent's class destructor.  This is so
+  // that if there are pending tasks that run, code that checks that it's on the
+  // correct ChromeThread succeeds.
+  Stop();
+
   AutoLock lock(lock_);
   chrome_threads_[identifier_] = NULL;
 #ifndef NDEBUG
   // Double check that the threads are ordererd correctly in the enumeration.
   for (int i = identifier_ + 1; i < ID_COUNT; ++i) {
     DCHECK(!chrome_threads_[i]) <<
         "Threads must be listed in the reverse order that they die";
   }
 #endif
 }
@@ skipping 84 matching lines @@
     }
   } else {
     delete task;
   }
 
   if (!guaranteed_to_outlive_target_thread)
     lock_.Release();
 
   return !!message_loop;
 }