Re-land: Implement ChromeVox Next menus.

chrome/browser/resources/chromeos/chromevox/host/interface/abstract_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.
 
 /**
  * @fileoverview Base class for Text-to-Speech engines that actually transform
  * text to speech.
  *
  */
 
@@ skipping 125 matching lines @@
 cvox.AbstractTts.prototype.increaseOrDecreaseProperty =
     function(propertyName, increase) {
       var min = this.propertyMin[propertyName];
       var max = this.propertyMax[propertyName];
       var step = this.propertyStep[propertyName];
       var current = this.ttsProperties[propertyName];
       current = increase ? current + step : current - step;
       this.ttsProperties[propertyName] = Math.max(Math.min(current, max), min);
     };
 
+/**
+ * Converts an engine property value to a percentage from 0.00 to 1.00.
+ * @param {string} property The property to convert.
+ * @return {?number} The percentage of the property.
+ */
+cvox.AbstractTts.prototype.propertyToPercentage = function(property) {
+  return (this.ttsProperties[property] - this.propertyMin[property]) /
+         Math.abs(this.propertyMax[property] - this.propertyMin[property]);
+};
 
 /**
  * Merges the given properties with the default ones. Always returns a
  * new object, so that you can safely modify the result of mergeProperties
  * without worrying that you're modifying an object used elsewhere.
  * @param {Object=} properties The properties to merge with the current ones.
  * @return {Object} The merged properties.
  * @protected
  */
 cvox.AbstractTts.prototype.mergeProperties = function(properties) {
@@ skipping 402 matching lines @@
           .format({'COUNT': count}) + ' ';
 };
 
 
 /**
  * @override
  */
 cvox.AbstractTts.prototype.getDefaultProperty = function(property) {
   return this.propertyDefault[property];
 };