Fix up SequencedWorkerPool in preparation for making it a TaskRunner

content/browser/browser_thread_impl.cc

 // 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.
 
 #include "content/browser/browser_thread_impl.h"
 
 #include "base/atomicops.h"
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/lazy_instance.h"
@@ skipping 34 matching lines @@
   // This array is protected by |lock|. The threads are not owned by this
   // array. Typically, the threads are owned on the UI thread by
   // content::BrowserMainLoop. BrowserThreadImpl objects remove themselves from
   // this array upon destruction.
   BrowserThreadImpl* threads[BrowserThread::ID_COUNT];
 
   // Only atomic operations are used on this array. The delegates are not owned
   // by this array, rather by whoever calls BrowserThread::SetDelegate.
   BrowserThreadDelegate* thread_delegates[BrowserThread::ID_COUNT];
 
-  // This pointer is deliberately leaked on shutdown. This allows the pool to
-  // implement "continue on shutdown" semantics.
-  base::SequencedWorkerPool* blocking_pool;
+  const scoped_refptr<base::SequencedWorkerPool> blocking_pool;
 };
 
 base::LazyInstance<BrowserThreadGlobals>::Leaky
     g_globals = LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
 
 BrowserThreadImpl::BrowserThreadImpl(ID identifier)
     : Thread(g_browser_thread_names[identifier]),
       identifier_(identifier) {
@@ skipping 324 matching lines @@
   AtomicWord* storage = reinterpret_cast<AtomicWord*>(
       &globals.thread_delegates[identifier]);
   AtomicWord old_pointer = base::subtle::NoBarrier_AtomicExchange(
       storage, reinterpret_cast<AtomicWord>(delegate));
 
   // This catches registration when previously registered.
   DCHECK(!delegate || !old_pointer);
 }
 
 }  // namespace content