Use InterstitialPage through a delegate interface instead of deriving from it.

chrome/browser/renderer_host/offline_resource_throttle.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 "chrome/browser/renderer_host/offline_resource_throttle.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 32 matching lines @@
         BrowserThread::IO, FROM_HERE, base::Bind(callback, true));
   } else {
     RenderViewHost* render_view_host =
         RenderViewHost::FromID(render_process_id, render_view_id);
     WebContents* web_contents = render_view_host ?
         render_view_host->delegate()->GetAsWebContents() : NULL;
     // There is a chance that the tab closed after we decided to show
     // the offline page on the IO thread and before we actually show the
     // offline page here on the UI thread.
     if (web_contents)
-      (new chromeos::OfflineLoadPage(web_contents, url, callback))->Show();
+      new chromeos::OfflineLoadPage(web_contents, url, callback);
   }
 }
 
 }  // namespace
 
 OfflineResourceThrottle::OfflineResourceThrottle(
     int render_process_id,
     int render_view_id,
     net::URLRequest* request,
     ChromeAppCacheService* appcache_service)
@@ skipping 64 matching lines @@
         base::Bind(
             &ShowOfflinePage,
             render_process_id_,
             render_view_id_,
             request_->url(),
             base::Bind(
                 &OfflineResourceThrottle::OnBlockingPageComplete,
                 AsWeakPtr())));
   }
 }