Fixed CHECKs for use of canceled ResourceContexts in ResourceDispatcherHostImpl.

content/public/browser/resource_context.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_RESOURCE_CONTEXT_H_
 #define CONTENT_PUBLIC_BROWSER_RESOURCE_CONTEXT_H_
 
 #include "base/supports_user_data.h"
 #include "content/common/content_export.h"
 
 namespace appcache {
 class AppCacheService;
 }
 
 namespace net {
 class HostResolver;
 class URLRequestContext;
 }
 
 namespace content {
 
 // ResourceContext contains the relevant context information required for
 // resource loading. It lives on the IO thread, although it is constructed on
 // the UI thread. It must be destructed on the IO thread.
 class CONTENT_EXPORT ResourceContext : public base::SupportsUserData {
  public:
   static appcache::AppCacheService* GetAppCacheService(
       ResourceContext* resource_context);
 
+  ResourceContext();
   virtual ~ResourceContext();
   virtual net::HostResolver* GetHostResolver() = 0;
   virtual net::URLRequestContext* GetRequestContext() = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RESOURCE_CONTEXT_H_