Clean up browser tests in Files.app.

chrome/test/data/extensions/api_test/file_manager_browsertest/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.
 
 /**
  * Extension ID of Files.app.
  * @type {string}
  * @const
  */
 var FILE_MANAGER_EXTENSIONS_ID = 'hhaomjibdihmijegdhdafkllkbggdgoj';
@@ skipping 10 matching lines @@
 function callRemoteTestUtil(func, appId, args, callback) {
   chrome.runtime.sendMessage(
       FILE_MANAGER_EXTENSIONS_ID, {
         func: func,
         appId: appId,
         args: args
       },
       callback);
 }
 
+/**
+ * Executes a sequence of test steps.
+ * @constructor
+ */
+function StepsRunner() {
+  /**
+   * List of steps.
+   * @type {Array.function>}
+   * @private
+   */
+  this.steps_ = [];
+}
+
+/**
+ * Creates a StepsRunner instance and runs the passed steps.
+ */
+StepsRunner.run = function(steps) {
+  var stepsRunner = new StepsRunner();
+  stepsRunner.run_(steps);
+};
+
+StepsRunner.prototype = {
+  /**
+   * @return {function} The next closure.
+   */
+  get next() {
+    return this.steps_.shift();
+  }
+};
+
+/**
+ * Runs a sequence of the added test steps.
+ * @type {Array.<function>} List of the sequential steps.
+ */
+StepsRunner.prototype.run_ = function(steps) {
+  this.steps_ = steps.slice(0);
+
+  // An extra step which acts as an empty callback for optional asynchronous
+  // calls in the last provided step.
+  this.steps_.push(function() {});
+
+  this.steps_ = this.steps_.map(function(f) {
+    return chrome.test.callbackPass(f.bind(this));
+  }.bind(this));
+
+  this.next();
+};
+
 chrome.test.runTests([
   // Waits for the C++ code to send a string identifying a test, then runs that
   // test.
   function testRunner() {
     var command = chrome.extension.inIncognitoContext ? 'which test guest' :
         'which test non-guest';
     chrome.test.sendMessage(command, function(testCaseName) {
       // Run one of the test cases defined in the testcase namespace, in
       // test_cases.js. The test case name is passed via StartTest call in
       // file_manager_browsertest.cc.
       if (testcase[testCaseName])
         testcase[testCaseName]();
       else
         chrome.test.fail('Bogus test name passed to testRunner()');
     });
   }
 ]);