[Extensions Bindings] Add enum support

chrome/test/data/extensions/api_test/native_bindings/background.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.
 
 if (!chrome || !chrome.test)
   throw new Error('chrome.test is undefined');
 
 // This is a good end-to-end test for two reasons. The first is obvious - it
 // tests a simple API and makes sure it behaves as expected, as well as testing
 // that other APIs are unavailable.
 // The second is that chrome.test is itself an extension API, and a rather
 // complex one. It requires both traditional bindings (renderer parses args,
 // passes info to browser process, browser process does work and responds, re-
 // enters JS) and custom JS bindings (in order to have our runTests, assert*
 // methods, etc). If any of these stages failed, the test itself would also
 // fail.
 chrome.test.runTests([
   function idleApi() {
     chrome.test.assertTrue(!!chrome.idle);
+    chrome.test.assertTrue(!!chrome.idle.IdleState);
+    chrome.test.assertTrue(!!chrome.idle.IdleState.IDLE);
+    chrome.test.assertTrue(!!chrome.idle.IdleState.ACTIVE);
     chrome.test.assertTrue(!!chrome.idle.queryState);
     chrome.idle.queryState(1000, function(state) {
       // Depending on the machine, this could come back as either idle or
       // active. However, all we're curious about is the bindings themselves
       // (not the API implementation), so as long as it's a possible response,
       // it's a success for our purposes.
-      // TODO(devlin): Update this to use chrome.idle.IdleState.[ACTIVE|IDLE]
-      // when we have enums in native bindings.
-      chrome.test.assertTrue(state == 'idle' || state == 'active', state);
+      chrome.test.assertTrue(state == chrome.idle.IdleState.IDLE ||
+                             state == chrome.idle.IdleState.ACTIVE);
       chrome.test.succeed();
     });
   },
   function nonexistentApi() {
     chrome.test.assertFalse(!!chrome.nonexistent);
     chrome.test.succeed();
   },
   function disallowedApi() {
     chrome.test.assertFalse(!!chrome.power);
     chrome.test.succeed();
   },
 ]);