Add "Show saved copy" button in dino page when there's offline copy

chrome/browser/net/net_error_tab_helper.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 CHROME_BROWSER_NET_NET_ERROR_TAB_HELPER_H_
 #define CHROME_BROWSER_NET_NET_ERROR_TAB_HELPER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 86 matching lines @@
 
   // Sanitizes |url| and shows a dialog for it.
   void RunNetworkDiagnostics(const GURL& url);
 
   // Shows the diagnostics dialog after its been sanitized, virtual for
   // testing.
   virtual void RunNetworkDiagnosticsHelper(const std::string& sanitized_url);
 
   // Relates to offline pages handling.
 #if defined(OS_ANDROID)
-  void SetHasOfflinePages(content::RenderFrameHost* render_frame_host);
+  void SetOfflinePageInfo(content::RenderFrameHost* render_frame_host,
+                          const GURL& url);
   void ShowOfflinePages();
-#endif
+  void LoadOfflineCopy(const GURL& url);
+  bool IsFromErrorPage() const;
+#endif  // defined(OS_ANDROID)
 
   // True if the last provisional load that started was for an error page.
   bool is_error_page_;
 
   // True if the helper has seen a main frame page load fail with a DNS error,
   // but has not yet seen a new page commit successfully afterwards.
   bool dns_error_active_;
 
   // True if the helper has seen an error page commit while |dns_error_active_|
   // is true.  (This should never be true if |dns_error_active_| is false.)
@@ skipping 12 matching lines @@
   BooleanPrefMember resolve_errors_with_web_service_;
 
   base::WeakPtrFactory<NetErrorTabHelper> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NetErrorTabHelper);
 };
 
 }  // namespace chrome_browser_net
 
 #endif  // CHROME_BROWSER_NET_NET_ERROR_TAB_HELPER_H_