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

chrome/renderer/resources/neterror.js

 // Copyright 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.
 
 function toggleHelpBox() {
   var helpBoxOuter = document.getElementById('details');
   helpBoxOuter.classList.toggle('hidden');
   var detailsButton = document.getElementById('details-button');
   if (helpBoxOuter.classList.contains('hidden'))
     detailsButton.innerText = detailsButton.detailsText;
@@ skipping 96 matching lines @@
     location = url;
   }
 }
 
 function showSavedCopyButtonClick() {
   if (window.errorPageController) {
     errorPageController.showSavedCopyButtonClick();
   }
 }
 
-function showSavedPagesButtonClick() {
+function showOfflinePagesButtonClick() {
   if (window.errorPageController) {
-    errorPageController.showSavedPagesButtonClick();
+    errorPageController.showOfflinePagesButtonClick();
   }
 }
 
+function showOfflineCopyButtonClick() {
+  if (window.errorPageController) {
+    errorPageController.showOfflineCopyButtonClick();
+  }
+}
+
 function detailsButtonClick() {
   if (window.errorPageController)
     errorPageController.detailsButtonClick();
 }
 
 /**
  * Replace the reload button with the Google cached copy suggestion.
  */
 function setUpCachedButton(buttonStrings) {
   var reloadButton = document.getElementById('reload-button');
@@ skipping 16 matching lines @@
 var primaryControlOnLeft = true;
 <if expr="is_macosx or is_ios or is_linux or is_android">
 primaryControlOnLeft = false;
 </if>
 
 function onDocumentLoad() {
   var controlButtonDiv = document.getElementById('control-buttons');
   var reloadButton = document.getElementById('reload-button');
   var detailsButton = document.getElementById('details-button');
   var showSavedCopyButton = document.getElementById('show-saved-copy-button');
-  var showSavedPagesButton = document.getElementById('show-saved-pages-button');
+  var showOfflinePagesButton =
+      document.getElementById('show-offline-pages-button');
+  var showOfflineCopyButton =
+      document.getElementById('show-offline-copy-button');
 
-  // "Show save pages" button will only be provided in ERR_INTERNET_DISCONNECTED
-  // page where "Reload" button will not be provided.
   var reloadButtonVisible = loadTimeData.valueExists('reloadButton') &&
       loadTimeData.getValue('reloadButton').msg;
   var showSavedCopyButtonVisible =
       loadTimeData.valueExists('showSavedCopyButton') &&
       loadTimeData.getValue('showSavedCopyButton').msg;
-  var showSavedPagesButtonVisible =
-      loadTimeData.valueExists('showSavedPagesButton') &&
-      loadTimeData.getValue('showSavedPagesButton').msg;
+  var showOfflinePagesButtonVisible =
+      loadTimeData.valueExists('showOfflinePagesButton') &&
+      loadTimeData.getValue('showOfflinePagesButton').msg;
+  var showOfflineCopyButtonVisible =
+      loadTimeData.valueExists('showOfflineCopyButton') &&
+      loadTimeData.getValue('showOfflineCopyButton').msg;
+
+  // "Show save pages" or "Show offline copy" button will only be provided in
+  // ERR_INTERNET_DISCONNECTED page where "Reload" button will not be provided.
+  var otherButton = reloadButton;
+  if (showOfflinePagesButtonVisible)
+    otherButton = showOfflinePagesButton;
+  if (showOfflineCopyButtonVisible)
+    otherButton = showOfflineCopyButton;
 
   var primaryButton, secondaryButton;
   if (showSavedCopyButton.primary) {
     primaryButton = showSavedCopyButton;
-    secondaryButton =
-        showSavedPagesButtonVisible ? showSavedPagesButton : reloadButton;
+    secondaryButton = otherButton;
   } else {
-    primaryButton =
-        showSavedPagesButtonVisible ? showSavedPagesButton : reloadButton;
+    primaryButton = otherButton;
     secondaryButton = showSavedCopyButton;
   }
 
   // Sets up the proper button layout for the current platform.
   if (primaryControlOnLeft) {
     buttons.classList.add('suggested-left');
     controlButtonDiv.insertBefore(secondaryButton, primaryButton);
   } else {
     buttons.classList.add('suggested-right');
     controlButtonDiv.insertBefore(primaryButton, secondaryButton);
   }
 
   // Check for Google cached copy suggestion.
   if (loadTimeData.valueExists('cacheButton')) {
     setUpCachedButton(loadTimeData.getValue('cacheButton'));
   }
 
   if (reloadButton.style.display == 'none' &&
       showSavedCopyButton.style.display == 'none' &&
-      showSavedPagesButton.style.display == 'none') {
+      showOfflinePagesButton.style.display == 'none' &&
+      showOfflineCopyButton.style.display == 'none') {
     detailsButton.classList.add('singular');
   }
 
 <if expr="not chromeos">
   // Hide the details button if there are no details to show.
   if (loadTimeData.valueExists('summary') &&
           !loadTimeData.getValue('summary').msg) {
     detailsButton.style.display = 'none';
   }
 </if>
 
   // Show control buttons.
   if (reloadButtonVisible || showSavedCopyButtonVisible ||
-      showSavedPagesButtonVisible) {
+      showOfflinePagesButtonVisible || showOfflineCopyButton) {
     controlButtonDiv.hidden = false;
 
     // Set the secondary button state in the cases of two call to actions.
-    if ((reloadButtonVisible || showSavedPagesButtonVisible) &&
+    if ((reloadButtonVisible || showOfflinePagesButtonVisible ||
+         showOfflineCopyButton) &&
         showSavedCopyButtonVisible) {
       secondaryButton.classList.add('secondary-button');
     }
   }
 
   // Add a main message paragraph.
   if (loadTimeData.valueExists('primaryParagraph')) {
     var p = document.querySelector('#main-message p');
     p.innerHTML = loadTimeData.getString('primaryParagraph');
     p.hidden = false;
   }
 }
 
 document.addEventListener('DOMContentLoaded', onDocumentLoad);