Adding a LaunchApp command to Chromedriver

chrome/test/chromedriver/extension/background.js

 // Copyright (c) 2013 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.
 
 /*
  * Checks for an extension error that occurred during the asynchronous call.
  * If an error occurs, will invoke the error callback and throw an exception.
  *
  * @param {function(!Error)} errCallback The callback to invoke for error
  *     reporting.
@@ skipping 53 matching lines @@
  */
 function updateWindow(updateInfo, callback, errCallback) {
   chrome.windows.getCurrent({}, function(window) {
     checkForExtensionError(errCallback);
     chrome.windows.update(window.id, updateInfo, function(window) {
       checkForExtensionError(errCallback);
       callback();
     });
   });
 }
+
+/**
+ * Launches an app with the specified id.
+ *
+ * @param {string} id The ID of the app to launch.
+ * @param {function()} callback Invoked when the launch event is complete.
+ * @param {function(!Error)} errCallback The callback to invoke for error
+ *     reporting.
+ */
+function launchApp(id, callback, errCallback) {
+  chrome.management.launchApp(id, function() {
+    checkForExtensionError(errCallback);
+    callback();
+  });
+}