Finish deinlining virtual methods.

net/proxy/proxy_script_fetcher.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.
 
 // ProxyScriptFetcher is an async interface for fetching a proxy auto config
 // script. It is specific to fetching a PAC script; enforces timeout, max-size,
 // status code.
 
 #ifndef NET_PROXY_PROXY_SCRIPT_FETCHER_H_
 #define NET_PROXY_PROXY_SCRIPT_FETCHER_H_
@@ skipping 30 matching lines @@
   //
   // Only one fetch is allowed to be outstanding at a time.
   virtual int Fetch(const GURL& url, string16* utf16_text,
                     CompletionCallback* callback) = 0;
 
   // Aborts the in-progress fetch (if any).
   virtual void Cancel() = 0;
 
   // Returns the request context that this fetcher uses to issue downloads,
   // or NULL.
-  virtual URLRequestContext* GetRequestContext() { return NULL; }
+  virtual URLRequestContext* GetRequestContext() = 0;
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_PROXY_SCRIPT_FETCHER_H_