Fix ChromeVox next tests to fail instead of timing out where applicable.

chrome/browser/resources/chromeos/chromevox/testing/mock_tts.js

 // Copyright 2014 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.
 
 /**
  * Mock tts class.
  * @constructor
  * @extends {cvox.TtsInterface}
  */
 var MockTts = function() {
@@ skipping 44 matching lines @@
   expectSpeechAfter: function(expectedText, opt_callback, opt_exact) {
     var expectation = {};
     if (this.expectations_.length == 0 && opt_callback)
       opt_callback();
     else
       expectation.startCallback = opt_callback;
     this.addExpectation_(expectedText, expectation, opt_exact);
   },
 
   /**
-   * Finishes expectations and calls testDone.
+   * Finishes expectations and calls {@code callback} afterwards.
+   * @param {Function} callback
    */
-  finishExpectations: function() {
-    this.expectSpeechAfter('', testDone);
+  finishExpectations: function(callback) {
+    this.expectSpeechAfter('', callback);
   },
 
   /**
    * @private
    * @param {string} expectedText Text expected spoken.
    * @param {{startCallback: function() : void,
    *     endCallback: function() : void}=} opt_expectation
    * @param {boolean=} opt_exact Expects an exact match.
    */
   addExpectation_: function(expectedText, opt_expectation, opt_exact) {
@@ skipping 42 matching lines @@
         matchingProperties.endCallback();
       }
       var nextExpectation = this.expectations_[0];
       if (nextExpectation && nextExpectation.startCallback)
         nextExpectation.startCallback();
     } else {
       this.expectations_.unshift(targetExpectation);
     }
   },
 };