Three way experiment for "Show saved copy" button.

components/error_page/common/net_error_info.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 COMPONENTS_ERROR_PAGE_COMMON_NET_ERROR_INFO_H_
 #define COMPONENTS_ERROR_PAGE_COMMON_NET_ERROR_INFO_H_
 
 // TODO(hashimoto): Change this to namespace error_page.
 namespace chrome_common_net {
 
 // Network error page events.  Used for UMA statistics.
 enum NetworkErrorPageEvent {
   NETWORK_ERROR_PAGE_SHOWN,                      // Error pages shown.
 
   NETWORK_ERROR_PAGE_RELOAD_BUTTON_SHOWN,        // Reload buttons shown.
   NETWORK_ERROR_PAGE_RELOAD_BUTTON_CLICKED,      // Reload button clicked.
   NETWORK_ERROR_PAGE_RELOAD_BUTTON_ERROR,        // Reload button clicked
                                                  // -> error.
 
-  NETWORK_ERROR_PAGE_LOAD_STALE_BUTTON_SHOWN,    // Load stale buttons shown.
-  NETWORK_ERROR_PAGE_LOAD_STALE_BUTTON_CLICKED,  // Load stale button clicked.
-  NETWORK_ERROR_PAGE_LOAD_STALE_BUTTON_ERROR,    // Load stale buttons -> error.
+  // Same for the "Show saved copy" button.
+  NETWORK_ERROR_PAGE_SHOW_SAVED_COPY_BUTTON_SHOWN,
+  NETWORK_ERROR_PAGE_SHOW_SAVED_COPY_BUTTON_CLICKED,
+  NETWORK_ERROR_PAGE_SHOW_SAVED_COPY_BUTTON_ERROR,
 
   NETWORK_ERROR_PAGE_MORE_BUTTON_CLICKED,        // More button clicked.
 
   NETWORK_ERROR_PAGE_BROWSER_INITIATED_RELOAD,   // Reload from browser.
 
   NETWORK_ERROR_PAGE_EVENT_MAX,
 };
 
 // The status of a DNS probe.
 //
@@ skipping 50 matching lines @@
 // Record specific error page events.
 void RecordEvent(NetworkErrorPageEvent event);
 
 // The error domain used to pass DNS probe statuses to the localized error
 // code.
 extern const char kDnsProbeErrorDomain[];
 
 }  // namespace chrome_common_net
 
 #endif  // COMPONENTS_ERROR_PAGE_COMMON_NET_ERROR_INFO_H_