Three way experiment for "Show saved copy" button.

chrome/renderer/net/net_error_helper.h

 // Copyright (c) 2013 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_RENDERER_NET_NET_ERROR_HELPER_H_
 #define CHROME_RENDERER_NET_NET_ERROR_HELPER_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 27 matching lines @@
     : public content::RenderFrameObserver,
       public content::RenderFrameObserverTracker<NetErrorHelper>,
       public content::RenderProcessObserver,
       public error_page::NetErrorHelperCore::Delegate {
  public:
   explicit NetErrorHelper(content::RenderFrame* render_view);
   ~NetErrorHelper() override;
 
   // Button press notification from error page.
   void ReloadButtonPressed();
-  void LoadStaleButtonPressed();
+  void ShowSavedCopyButtonPressed();
   void MoreButtonPressed();
 
   // RenderFrameObserver implementation.
   void DidStartProvisionalLoad() override;
   void DidCommitProvisionalLoad(bool is_new_navigation,
                                 bool is_same_page_navigation) override;
   void DidFinishLoad() override;
   void OnStop() override;
   void WasShown() override;
   void WasHidden() override;
@@ skipping 24 matching lines @@
   // Called when a link with the given tracking ID is pressed.
   void TrackClick(int tracking_id);
 
  private:
   // NetErrorHelperCore::Delegate implementation:
   void GenerateLocalizedErrorPage(
       const blink::WebURLError& error,
       bool is_failed_post,
       scoped_ptr<error_page::ErrorPageParams> params,
       bool* reload_button_shown,
-      bool* load_stale_button_shown,
+      bool* show_saved_copy_button_shown,
       std::string* html) const override;
   void LoadErrorPageInMainFrame(const std::string& html,
                                 const GURL& failed_url) override;
   void EnablePageHelperFunctions() override;
   void UpdateErrorPage(const blink::WebURLError& error,
                        bool is_failed_post) override;
   void FetchNavigationCorrections(
       const GURL& navigation_correction_url,
       const std::string& navigation_correction_request_body) override;
   void CancelFetchNavigationCorrections() override;
@@ skipping 17 matching lines @@
 
   scoped_ptr<content::ResourceFetcher> correction_fetcher_;
   scoped_ptr<content::ResourceFetcher> tracking_fetcher_;
 
   scoped_ptr<error_page::NetErrorHelperCore> core_;
 
   DISALLOW_COPY_AND_ASSIGN(NetErrorHelper);
 };
 
 #endif  // CHROME_RENDERER_NET_NET_ERROR_HELPER_H_