WebUI: Add cr-policy-pref-indicator tests

chrome/test/data/webui/cr_elements/cr_elements_browsertest.js

 // Copyright 2016 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 Tests for shared Polymer elements. */
 
 /** @const {string} Path to source root. */
 var ROOT_PATH = '../../../../../';
 
 // Polymer BrowserTest fixture.
@@ skipping 115 matching lines @@
       'chrome://resources/cr_elements/cr_action_menu/cr_action_menu.html',
 
   extraLibraries: CrElementsBrowserTest.prototype.extraLibraries.concat([
     'cr_action_menu_test.js',
   ]),
 };
 
 TEST_F('CrElementsActionMenuTest', 'All', function() {
   mocha.run();
 });
+
+function CrElementsPolicyPrefIndicatorTest() {}
+
+CrElementsPolicyPrefIndicatorTest.prototype = {
+  __proto__: CrElementsBrowserTest.prototype,
+
+  /** @override */
+  browsePreload:
+      'chrome://resources/cr_elements/policy/cr_policy_pref_indicator.html',
+
+  /** @override */
+  extraLibraries: CrElementsBrowserTest.prototype.extraLibraries.concat([
+    // settings_private.js is needed just to define types, e.g.
+    // chrome.settingsPrivate.PrefType.
+    '../../../../../third_party/closure_compiler/externs/settings_private.js',

[Dan Beam, 2017/01/18 01:06:34]

it's really a huge bummer to execute externs

[Dan Beam, 2017/01/18 01:06:52]

don't we have a thing called "interfaces" for this instead?

[stevenjb, 2017/01/18 23:13:03]

*_interface.js explicitly can not be executed (and does not contain types). It
contains a prototype for the interface and types for events.

The only alternative I can think of would be to create something like
*_private_types.js in this directory for the tests (copy/pasting types from the
externs file). I am open to suggestions.

[Dan Beam, 2017/02/16 23:14:49]

not lgtm

+    'cr_policy_pref_indicator_tests.js',
+  ]),
+};
+
+TEST_F('CrElementsPolicyPrefIndicatorTest', 'All', function() {
+  mocha.run();
+});