Allows endCallbacks in tts to queue up speech in the speech queue and simplify speech output logic.

chrome/browser/resources/chromeos/chromevox/cvox2/background/background_test.extjs

 // 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.
 
 // Include test fixture.
 GEN_INCLUDE(['../../testing/chromevox_next_e2e_test_base.js']);
 
 GEN_INCLUDE(['../../testing/mock_tts.js']);
 
 /**
@@ skipping 157 matching lines @@
     var expect = cvox.ChromeVox.tts.expectSpeech.bind(cvox.ChromeVox.tts);
     expect('apple Menu item  1 of 3 ', sendDownToSelect, true);
     expect('grape  2 of 3 ', sendDownToSelect, true);
     expect('banana  3 of 3 ', testDone, true);
     cvox.ChromeVox.tts.finishExpectations();
   }.bind(this));
 });
 
 TEST_F('BackgroundTest', 'MANUAL_ContinuousRead', function() {
   this.runWithLoadedTree(this.linksAndHeadingsDoc, function() {
-    var doCmd = this.doCmd.bind(this);
-    var expect =
-        cvox.ChromeVox.tts.expectSpeechAfter.bind(cvox.ChromeVox.tts);
-    var sendEndEvent = function() {
-        window.setTimeout(function() {
-          this.sendEndEvent();
-      }.bind(this), 0);
-    }.bind(cvox.ChromeVox.tts);
-
-    expect('start', doCmd('continuousRead'));
-    expect('alpha Link', sendEndEvent);
-    expect('beta Link', sendEndEvent);
-    expect('Heading charlie', sendEndEvent);
+    cvox.ChromeVox.tts.expectSpeech('start');
+    cvox.ChromeVox.tts.expectSpeechAfter('start', this.doCmd('continuousRead'));
+    cvox.ChromeVox.tts.expectSpeech('alpha Link');
+    cvox.ChromeVox.tts.expectSpeech('beta Link');
+    cvox.ChromeVox.tts.expectSpeech('Heading charlie', testDone);
     cvox.ChromeVox.tts.finishExpectations();
   }.bind(this));
 });