Make |context| passed to queryRequiredElement optional

ui/file_manager/gallery/js/slide_mode.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.
 
 /**
  * Slide mode displays a single image and has a set of controls to navigate
  * between the images and to edit an image.
  *
  * @param {!HTMLElement} container Main container element.
  * @param {!HTMLElement} content Content container element.
@@ skipping 204 matching lines @@
   // ----------------------------------------------------------------
   // Initializes the UI.
 
   /**
    * Container for displayed image.
    * @type {!HTMLElement}
    * @private
    * @const
    */
   this.imageContainer_ = util.createChild(queryRequiredElement(
-      this.document_, '.content'), 'image-container');
+      '.content', this.document_), 'image-container');
 
   this.document_.addEventListener('click', this.onDocumentClick_.bind(this));
 
   /**
    * Overwrite options and info bubble.
    * @type {!HTMLElement}
    * @private
    * @const
    */
-  this.options_ = queryRequiredElement(this.bottomToolbar_, '.options');
+  this.options_ = queryRequiredElement('.options', this.bottomToolbar_);
 
   /**
    * @type {!HTMLElement}
    * @private
    * @const
    */
-  this.savedLabel_ = queryRequiredElement(this.options_, '.saved');
+  this.savedLabel_ = queryRequiredElement('.saved', this.options_);
 
   /**
    * @private {!PaperCheckboxElement}
    * @const
    */
   this.overwriteOriginalCheckbox_ = /** @type {!PaperCheckboxElement} */
-      (queryRequiredElement(this.options_, '.overwrite-original'));
+      (queryRequiredElement('.overwrite-original', this.options_));
   this.overwriteOriginalCheckbox_.addEventListener('change',
       this.onOverwriteOriginalCheckboxChanged_.bind(this));
 
   /**
    * @private {!FilesToast}
    * @const
    */
   this.filesToast_ = /** @type {!FilesToast} */
-      (queryRequiredElement(document, 'files-toast'));
+      (queryRequiredElement('files-toast'));
 
   /**
    * @private {!HTMLElement}
    * @const
    */
-  this.bubble_ = queryRequiredElement(this.bottomToolbar_, '.bubble');
+  this.bubble_ = queryRequiredElement('.bubble', this.bottomToolbar_);
 
-  var bubbleContent = queryRequiredElement(this.bubble_, '.content');
+  var bubbleContent = queryRequiredElement('.content', this.bubble_);
   // GALLERY_OVERWRITE_BUBBLE contains <br> tag inside message.
   bubbleContent.innerHTML = strf('GALLERY_OVERWRITE_BUBBLE');
 
-  var bubbleClose = queryRequiredElement(this.bubble_, '.close-x');
+  var bubbleClose = queryRequiredElement('.close-x', this.bubble_);
   bubbleClose.addEventListener('click', this.onCloseBubble_.bind(this));
 
   /**
    * Ribbon and related controls.
    * @type {!HTMLElement}
    * @private
    * @const
    */
   this.arrowBox_ = util.createChild(this.container_, 'arrow-box');
 
@@ skipping 17 matching lines @@
       this.arrowBox_, 'arrow right tool dimmable');
   this.arrowRight_.addEventListener('click',
       this.advanceManually.bind(this, 1));
   util.createChild(this.arrowRight_);
 
   /**
    * @type {!HTMLElement}
    * @private
    * @const
    */
-  this.ribbonSpacer_ = queryRequiredElement(this.bottomToolbar_,
-      '.ribbon-spacer');
+  this.ribbonSpacer_ = queryRequiredElement('.ribbon-spacer',
+      this.bottomToolbar_);
 
   /**
    * @type {!Ribbon}
    * @private
    * @const
    */
   this.ribbon_ = new Ribbon(this.document_, window, this.dataModel_,
       this.selectionModel_, thumbnailModel);
   this.ribbonSpacer_.appendChild(this.ribbon_);
 
   util.createChild(this.container_, 'spinner');
 
   /**
    * @type {!HTMLElement}
    * @const
    */
-  var slideShowButton = queryRequiredElement(this.topToolbar_,
-      'paper-button.slideshow');
+  var slideShowButton = queryRequiredElement('paper-button.slideshow',
+      this.topToolbar_);
   slideShowButton.addEventListener('click',
       this.startSlideshow.bind(this, SlideMode.SLIDESHOW_INTERVAL_FIRST));
 
   /**
    * @type {!HTMLElement}
    * @const
    */
   var slideShowToolbar = util.createChild(
       this.container_, 'tool slideshow-toolbar');
   util.createChild(slideShowToolbar, 'slideshow-play').
       addEventListener('click', this.toggleSlideshowPause_.bind(this));
   util.createChild(slideShowToolbar, 'slideshow-end').
       addEventListener('click', this.stopSlideshow_.bind(this));
 
   // Editor.
   /**
    * @type {!HTMLElement}
    * @private
    * @const
    */
-  this.editButton_ = queryRequiredElement(this.topToolbar_, 'button.edit');
+  this.editButton_ = queryRequiredElement('button.edit', this.topToolbar_);
   GalleryUtil.decorateMouseFocusHandling(this.editButton_);
   this.editButton_.addEventListener('click', this.toggleEditor.bind(this));
 
   /**
    * @private {!FilesToggleRipple}
    * @const
    */
   this.editButtonToggleRipple_ = /** @type {!FilesToggleRipple} */
       (assert(this.editButton_.querySelector('files-toggle-ripple')));
 
   /**
    * @type {!HTMLElement}
    * @private
    * @const
    */
-  this.printButton_ = queryRequiredElement(
-      this.topToolbar_, 'paper-button.print');
+  this.printButton_ = queryRequiredElement('paper-button.print',
+      this.topToolbar_);
   this.printButton_.addEventListener('click', this.print_.bind(this));
 
   /**
    * @type {!HTMLElement}
    * @private
    * @const
    */
-  this.editBarSpacer_ = queryRequiredElement(this.bottomToolbar_,
-      '.edit-bar-spacer');
+  this.editBarSpacer_ = queryRequiredElement('.edit-bar-spacer',
+      this.bottomToolbar_);
 
   /**
    * @type {!HTMLElement}
    * @private
    * @const
    */
   this.editBarMain_ = util.createChild(this.editBarSpacer_, 'edit-main');
 
   /**
    * @type {!HTMLElement}
@@ skipping 1542 matching lines @@
   var event = assertInstanceof(event, MouseEvent);
   var viewport = this.slideMode_.getViewport();
   if (!this.enabled_ || !viewport.isZoomed())
     return;
   this.stopOperation();
   viewport.setOffset(
       viewport.getOffsetX() + event.wheelDeltaX,
       viewport.getOffsetY() + event.wheelDeltaY);
   this.slideMode_.applyViewportChange();
 };