Add empty constructor/destructor to ResourceContext on iOS

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/basictypes.h"
 #include "base/supports_user_data.h"
+#include "build/build_config.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:
+#if defined(OS_IOS)
+  virtual ~ResourceContext() {}
+#else
   ResourceContext();
   virtual ~ResourceContext();
+#endif
   virtual net::HostResolver* GetHostResolver() = 0;
 
   // DEPRECATED: This is no longer a valid given isolated apps/sites and
   // storage partitioning. This getter returns the default context associated
   // with a BrowsingContext.
   virtual net::URLRequestContext* GetRequestContext() = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RESOURCE_CONTEXT_H_