Fix some accessibility issues in image editing.

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.
 
 /**
  * ImageEditor is the top level object that holds together and connects
  * everything needed for image editing.
  *
  * @param {!Viewport} viewport The viewport.
  * @param {!ImageView} imageView The ImageView containing the images to edit.
@@ skipping 1124 matching lines @@
     parent, displayStringFunction, opt_updateCallback, opt_showActionButtons) {
   this.wrapper_ = parent;
   this.displayStringFunction_ = displayStringFunction;
 
   /**
    * @type {?function(Object)}
    * @private
    */
   this.updateCallback_ = opt_updateCallback || null;
 
-  // Create action buttons.
+  /**
+   * @private {!HTMLElement}
+   */
+  this.container_ = /** @type {!HTMLElement} */ (document.createElement('div'));
+  this.container_.classList.add('container');
+  this.wrapper_.appendChild(this.container_);
+
+    // Create action buttons.
   if (opt_showActionButtons) {
     var actionButtonsLayer = document.createElement('div');
     actionButtonsLayer.classList.add('action-buttons');
 
     this.cancelButton_ = ImageEditor.Toolbar.createButton_(
         'GALLERY_CANCEL_LABEL', ImageEditor.Toolbar.ButtonType.LABEL_UPPER_CASE,
         this.onCancelClicked_.bind(this), 'cancel');
     actionButtonsLayer.appendChild(this.cancelButton_);
 
     this.doneButton_ = ImageEditor.Toolbar.createButton_(
         'GALLERY_DONE', ImageEditor.Toolbar.ButtonType.LABEL_UPPER_CASE,
         this.onDoneClicked_.bind(this), 'done');
     actionButtonsLayer.appendChild(this.doneButton_);
 
     this.wrapper_.appendChild(actionButtonsLayer);
   }
-
-  /**
-   * @private {!HTMLElement}
-   */
-  this.container_ = /** @type {!HTMLElement} */ (document.createElement('div'));
-  this.container_.classList.add('container');
-  this.wrapper_.appendChild(this.container_);
 };
 
 ImageEditor.Toolbar.prototype.__proto__ = cr.EventTarget.prototype;
 
 /**
  * Height of the toolbar.
  * @const {number}
  */
 ImageEditor.Toolbar.HEIGHT = 48; // px
 
@@ skipping 268 matching lines @@
 
 /**
  * Show/hide the toolbar.
  * @param {boolean} on True if show.
  */
 ImageEditor.Toolbar.prototype.show = function(on) {
   if (!this.wrapper_.firstChild)
     return;  // Do not show empty toolbar;
 
   this.wrapper_.hidden = !on;
+
+  // Focus the first input on the toolbar.
+  if (on) {
+    var input = this.container_.querySelector(
+       'button, paper-button, input, paper-input, paper-slider');
+    if (input)
+      input.focus();
+  }
 };
 
 /** A prompt panel for the editor.
  *
  * @param {!HTMLElement} container Container element.
  * @param {function(string, ...string)} displayStringFunction A formatting
  *     function.
  * @constructor
  * @struct
  */
@@ skipping 129 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);
 };