Gallery.app: Add buttons to the cropping mode to specifying the aspect ratio.

ui/file_manager/gallery/js/image_editor/image_editor.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.
 
 'use strict';
 
 /**
  * ImageEditor is the top level object that holds together and connects
  * everything needed for image editing.
  *
@@ skipping 883 matching lines @@
  * A toolbar for the ImageEditor.
  * @param {HTMLElement} parent The parent element.
  * @param {function} displayStringFunction A string formatting function.
  * @param {function} updateCallback The callback called when controls change.
  * @constructor
  */
 ImageEditor.Toolbar = function(parent, displayStringFunction, updateCallback) {
   this.wrapper_ = parent;
   this.displayStringFunction_ = displayStringFunction;
   this.updateCallback_ = updateCallback;
+  Object.seal(this);
+};
+
+ImageEditor.Toolbar.prototype = {
+  get element() {
+    return this.wrapper_;
+  }
 };
 
 /**
  * Clear the toolbar.
  */
 ImageEditor.Toolbar.prototype.clear = function() {
   ImageUtil.removeChildren(this.wrapper_);
 };
 
 /**
@@ skipping 32 matching lines @@
  *
  * @param {string} name Button name.
  * @param {string} title Button title.
  * @param {function} handler onClick handler.
  * @param {string=} opt_class Extra class name.
  * @return {HTMLElement} The added button.
  */
 ImageEditor.Toolbar.prototype.addButton = function(
     name, title, handler, opt_class) {
   var button = this.create_('button');
-  if (opt_class) button.classList.add(opt_class);
+  if (opt_class)
+    button.classList.add(opt_class);
   var label = this.create_('span');
   label.textContent = this.displayStringFunction_(title);
   button.appendChild(label);
   button.label = this.displayStringFunction_(title);
   button.title = this.displayStringFunction_(title);
   button.addEventListener('click', handler, false);
   return this.add(button);
 };
 
 /**
@@ skipping 204 matching lines @@
 
 /**
  * Hide the prompt.
  */
 ImageEditor.Prompt.prototype.hide = function() {
   if (!this.prompt_) return;
   this.prompt_.setAttribute('state', 'fadeout');
   // Allow some time for the animation to play out.
   this.setTimer(this.reset.bind(this), 500);
 };