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

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

Index: chrome/browser/resources/settings/site_settings/site_settings_behavior.js
diff --git a/chrome/browser/resources/settings/site_settings/site_settings_behavior.js b/chrome/browser/resources/settings/site_settings/site_settings_behavior.js
index 9857b9cb9d84faded7fa3e333c52157febdfa13d..e59284b8f07e3afb03f25b0a9e7a2328410b709c 100644
--- a/chrome/browser/resources/settings/site_settings/site_settings_behavior.js
+++ b/chrome/browser/resources/settings/site_settings/site_settings_behavior.js
@@ -262,10 +262,12 @@ var SiteSettingsBehaviorImpl = {
                 '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');