Update chrome.settingsPrivate to support CrOS-only settings.

chrome/test/data/extensions/api_test/settings_private/test.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.
 
 // This just tests the interface. It does not test for specific results, only
 // that callbacks are correctly invoked, expected parameters are correct,
 // and failures are detected.
 
 var kTestPrefName = 'download.default_directory';
 var kTestPrefValue = '/Downloads';
@@ skipping 10 matching lines @@
   function setPref() {
     chrome.settingsPrivate.setPref(
         kTestPrefName,
         kTestPrefValue,
         kTestPageId,
         function(success) {
           callbackResult(success);
           chrome.test.succeed();
         });
   },
+  function setPref_CrOSSetting() {
+    chrome.settingsPrivate.setPref(
+        'cros.accounts.allowBWSI',
+        false,
+        kTestPageId,
+        function(success) {
+          callbackResult(success);
+          chrome.test.succeed();
+        });
+  },
   function getPref() {
     chrome.settingsPrivate.getPref(
         kTestPrefName,
         function(value) {
           chrome.test.assertTrue(value !== null);
           callbackResult(true);
           chrome.test.succeed();
         });
   },
+  function getPref_CrOSSetting() {
+    chrome.settingsPrivate.getPref(
+        'cros.accounts.allowBWSI',
+        function(value) {
+          chrome.test.assertTrue(value !== null);
+          callbackResult(true);
+          chrome.test.succeed();
+        });
+  },
   function getAllPrefs() {
     chrome.settingsPrivate.getAllPrefs(
         function(prefs) {
           chrome.test.assertTrue(prefs.length > 0);
           callbackResult(true);
           chrome.test.succeed();
         });
   },
   function onPrefsChanged() {
     chrome.settingsPrivate.onPrefsChanged.addListener(function(prefs) {
       chrome.test.assertTrue(prefs.length > 0);
       chrome.test.assertEq(kTestPrefName, prefs[0].key);
       chrome.test.assertEq(kTestPrefValue, prefs[0].value);
       callbackResult(true);
       chrome.test.succeed();
     });
 
     chrome.settingsPrivate.setPref(
         kTestPrefName,
         kTestPrefValue,
         kTestPageId,
         function() {});
   },
+  function onPrefsChanged_CrOSSetting() {
+    chrome.settingsPrivate.onPrefsChanged.addListener(function(prefs) {
+      chrome.test.assertTrue(prefs.length > 0);
+      chrome.test.assertEq('cros.accounts.allowBWSI', prefs[0].key);
+      chrome.test.assertEq(false, prefs[0].value);
+      callbackResult(true);
+      chrome.test.succeed();
+    });
+
+    chrome.settingsPrivate.setPref(
+        'cros.accounts.allowBWSI',
+        false,
+        kTestPageId,
+        function() {});
+  },
 ];
 
 var testToRun = window.location.search.substring(1);
 chrome.test.runTests(availableTests.filter(function(op) {
   return op.name == testToRun;
 }));