Add sessionType and playStoreStatus to chromeosInfoPrivate.

chrome/test/data/extensions/api_test/chromeos_info_private/extended/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.
+
+chrome.app.runtime.onLaunched.addListener(function() {
+  chrome.test.getConfig(function(config) {
+    var testName = config.customArg;
+    if (!testName) {
+      chrome.test.fail("Missing test name.");
+      return;
+    }
+    chrome.chromeosInfoPrivate.get(['sessionType', 'playStoreStatus'],
+        function (values) {
+      if (testName == 'kiosk') {
+        chrome.test.assertEq('kiosk', values['sessionType']);
+      } else if (testName == 'arc available') {
+        chrome.test.assertEq('available', values['playStoreStatus']);
+      } else if (testName == 'arc enabled') {
+        chrome.test.assertEq('enabled', values['playStoreStatus']);
+      }
+      chrome.test.succeed();
+    });
+  });
+});