Adding a LaunchApp command to Chromedriver

chrome/test/chromedriver/extension/background.js

Index: chrome/test/chromedriver/extension/background.js
diff --git a/chrome/test/chromedriver/extension/background.js b/chrome/test/chromedriver/extension/background.js
index 9158d6f5d72672bafc3bf7260cfe83d7771ebddb..9655ffa72b7f6d27cc51d67156dccc9a387e81ed 100644
--- a/chrome/test/chromedriver/extension/background.js
+++ b/chrome/test/chromedriver/extension/background.js
@@ -71,3 +71,18 @@ function updateWindow(updateInfo, callback, errCallback) {
     });
   });
 }
+
+/**
+ * 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();
+  });
+}