Revert "Revert "Const-ify RefCountedThreadSafe::AddRef and Release.""

chrome/service/net/service_url_request_context.h

 // Copyright (c) 2010 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 CHROME_SERVICE_NET_SERVICE_URL_REQUEST_CONTEXT_H_
 #define CHROME_SERVICE_NET_SERVICE_URL_REQUEST_CONTEXT_H_
 #pragma once
 
 #include <string>
 
@@ skipping 41 matching lines @@
 
  private:
   std::string user_agent_;
 };
 
 class ServiceURLRequestContextGetter : public URLRequestContextGetter {
  public:
   ServiceURLRequestContextGetter();
 
   virtual URLRequestContext* GetURLRequestContext();
-  virtual scoped_refptr<base::MessageLoopProxy> GetIOMessageLoopProxy();
+  virtual scoped_refptr<base::MessageLoopProxy> GetIOMessageLoopProxy() const;
 
   void set_user_agent(const std::string& ua) {
     user_agent_ = ua;
   }
  private:
   virtual ~ServiceURLRequestContextGetter();
 
   std::string user_agent_;
   scoped_refptr<URLRequestContext> url_request_context_;
   scoped_refptr<base::MessageLoopProxy> io_message_loop_proxy_;
 };
 
 #endif  // CHROME_SERVICE_NET_SERVICE_URL_REQUEST_CONTEXT_H_