MD Settings: Fix site data details regression and add test.

chrome/test/data/webui/settings/test_site_settings_prefs_browser_proxy.js

Index: chrome/test/data/webui/settings/test_site_settings_prefs_browser_proxy.js
diff --git a/chrome/test/data/webui/settings/test_site_settings_prefs_browser_proxy.js b/chrome/test/data/webui/settings/test_site_settings_prefs_browser_proxy.js
index 46d3bfa7d967b60e6fb2799a3834465d6bdb94a6..e7886156ee68a4d00fb8dd697f6d0e43863a20f3 100644
--- a/chrome/test/data/webui/settings/test_site_settings_prefs_browser_proxy.js
+++ b/chrome/test/data/webui/settings/test_site_settings_prefs_browser_proxy.js
@@ -48,6 +48,7 @@ var TestSiteSettingsPrefsBrowserProxy = function() {
   settings.TestBrowserProxy.call(this, [
     'fetchUsbDevices',
     'fetchZoomLevels',
+    'getCookieDetails',
     'getDefaultValueForContentType',
     'getExceptionList',
     'observeProtocolHandlers',
@@ -72,6 +73,9 @@ var TestSiteSettingsPrefsBrowserProxy = function() {
 
   /** @private {!Array<!ProtocolEntry>} */
   this.protocolHandlers_ = [];
+
+  /** @private {?CookieList} */
+  this.cookieDetails_ = null;
 };
 
 TestSiteSettingsPrefsBrowserProxy.prototype = {
@@ -126,6 +130,19 @@ TestSiteSettingsPrefsBrowserProxy.prototype = {
   },
 
   /** @override */
+  getCookieDetails: function(site) {
+    this.methodCalled('getCookieDetails', site);
+    return Promise.resolve(this.cookieDetails_  || {id: '', children: []});
+  },
+
+  /**
+   * @param {!CookieList} cookieList
+   */
+  setCookieDetails: function(cookieList) {
+    this.cookieDetails_ = cookieList;
+  },
+
+  /** @override */
   getDefaultValueForContentType: function(contentType) {
     this.methodCalled('getDefaultValueForContentType', contentType);