Site Settings Desktop: Implement tri-state 'Delete local data on exit'.

chrome/browser/resources/settings/site_settings/site_settings_behavior.js

 // Copyright 2015 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.
 
 /**
  * @fileoverview Behavior common to Site Settings classes.
  */
 
 /** @polymerBehavior */
 var SiteSettingsBehaviorImpl = {
@@ skipping 244 matching lines @@
       case settings.ContentSettingsTypes.MIC:
         // "Ask before accessing (recommended)" vs "Blocked".
         if (!categoryEnabled) {
           return loadTimeData.getString('siteSettingsBlocked');
         }
         return showRecommendation ?
             loadTimeData.getString(
                 'siteSettingsAskBeforeAccessingRecommended') :
             loadTimeData.getString('siteSettingsAskBeforeAccessing');
       case settings.ContentSettingsTypes.COOKIES:
-        // "Allow sites to save and read cookie data" vs "Blocked".
-        if (!categoryEnabled) {
+        // Tri-state: "Allow sites to save and read cookie data" vs "Blocked"
+        //     vs "Keep local data only until you quit your browser".
+        if (setting == settings.PermissionValues.BLOCK)
           return loadTimeData.getString('siteSettingsBlocked');
-        }
+        if (setting == settings.PermissionValues.SESSION_ONLY)
+          return loadTimeData.getString('deleteDataPostSession');
         return showRecommendation ?
             loadTimeData.getString('siteSettingsCookiesAllowedRecommended') :
             loadTimeData.getString('siteSettingsCookiesAllowed');
       case settings.ContentSettingsTypes.PROTOCOL_HANDLERS:
         // "Allow sites to ask to become default handlers" vs "Blocked".
         if (!categoryEnabled) {
           return loadTimeData.getString('siteSettingsHandlersBlocked');
         }
         return showRecommendation ?
             loadTimeData.getString('siteSettingsHandlersAskRecommended') :
@@ skipping 147 matching lines @@
   computeIsSettingEnabled: function(category, setting) {
     // FullScreen is Allow vs. Ask.
     return category == settings.ContentSettingsTypes.FULLSCREEN ?
         setting != settings.PermissionValues.ASK :
         setting != settings.PermissionValues.BLOCK;
   },
 };
 
 /** @polymerBehavior */
 var SiteSettingsBehavior = [SiteSettingsBehaviorImpl];