Turn on verbose flag for compiling file_manager.

ui/file_manager/gallery/js/image_editor/image_transform.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.
 
 /**
  * Crop mode.
  *
  * @extends {ImageEditor.Mode}
  * @constructor
  * @struct
  */
 ImageEditor.Mode.Crop = function() {
   ImageEditor.Mode.call(this, 'crop', 'GALLERY_CROP');
 
   this.paddingTop = ImageEditor.Mode.Crop.MOUSE_GRAB_RADIUS;
   this.paddingBottom = ImageEditor.Mode.Crop.MOUSE_GRAB_RADIUS;
 
   /**
-   * @type {HTMLDivElement}
+   * @type {HTMLElement}
    * @private
    */
   this.domOverlay_ = null;
 
   /**
-   * @type {HTMLDivElement}
+   * @type {HTMLElement}
    * @private
    */
   this.shadowTop_ = null;
 
   /**
-   * @type {HTMLDivElement}
+   * @type {HTMLElement}
    * @private
    */
   this.middleBox_ = null;
 
   /**
-   * @type {HTMLDivElement}
+   * @type {HTMLElement}
    * @private
    */
   this.shadowLeft_ = null;
 
   /**
-   * @type {HTMLDivElement}
+   * @type {HTMLElement}
    * @private
    */
   this.cropFrame_ = null;
 
   /**
-   * @type {HTMLDivElement}
+   * @type {HTMLElement}
    * @private
    */
   this.shadowRight_ = null;
 
   /**
-   * @type {HTMLDivElement}
+   * @type {HTMLElement}
    * @private
    */
   this.shadowBottom_ = null;
 
   /**
    * @type {?function()}
    * @private
    */
   this.onViewportResizedBound_ = null;
 
   /**
    * @type {DraggableRect}
    * @private
    */
   this.cropRect_ = null;
 };
 
 ImageEditor.Mode.Crop.prototype = {__proto__: ImageEditor.Mode.prototype};
 
 /**
  * Sets the mode up.
  * @override
  */
 ImageEditor.Mode.Crop.prototype.setUp = function() {
   ImageEditor.Mode.prototype.setUp.apply(this, arguments);
 
   var container = this.getImageView().container_;
   var doc = container.ownerDocument;
 
-  this.domOverlay_ = doc.createElement('div');
+  this.domOverlay_ = assertInstanceof(doc.createElement('div'), HTMLElement);

[Dan Beam, 2015/10/21 01:35:26]

assertInstanceof is not required, createElement only returns !Element

https://github.com/google/closure-compiler/blob/04dd916be73f961f489906231cfb1...

[fukino, 2015/10/21 04:00:28]

Do you suggest to use /** @type {!HTMLElement} */ instead of assertInstanceof()?
I agree with it, since check using instanceof looks redundant in this case.

I changed these assertInstanceof to type cast.
Please let me know if you suggest to change the type of this.domOverlay_ from
HTMLElement to Element.

   this.domOverlay_.className = 'crop-overlay';
   container.appendChild(this.domOverlay_);
 
-  this.shadowTop_ = doc.createElement('div');
+  this.shadowTop_ = assertInstanceof(doc.createElement('div'), HTMLElement);
   this.shadowTop_.className = 'shadow';
   this.domOverlay_.appendChild(this.shadowTop_);
 
-  this.middleBox_ = doc.createElement('div');
+  this.middleBox_ = assertInstanceof(doc.createElement('div'), HTMLElement);
   this.middleBox_.className = 'middle-box';
   this.domOverlay_.appendChild(this.middleBox_);
 
-  this.shadowLeft_ = doc.createElement('div');
+  this.shadowLeft_ = assertInstanceof(doc.createElement('div'), HTMLElement);
   this.shadowLeft_.className = 'shadow';
   this.middleBox_.appendChild(this.shadowLeft_);
 
-  this.cropFrame_ = doc.createElement('div');
+  this.cropFrame_ = assertInstanceof(doc.createElement('div'), HTMLElement);
   this.cropFrame_.className = 'crop-frame';
   this.middleBox_.appendChild(this.cropFrame_);
 
-  this.shadowRight_ = doc.createElement('div');
+  this.shadowRight_ = assertInstanceof(doc.createElement('div'), HTMLElement);
   this.shadowRight_.className = 'shadow';
   this.middleBox_.appendChild(this.shadowRight_);
 
-  this.shadowBottom_ = doc.createElement('div');
+  this.shadowBottom_ = assertInstanceof(doc.createElement('div'), HTMLElement);
   this.shadowBottom_.className = 'shadow';
   this.domOverlay_.appendChild(this.shadowBottom_);
 
   var cropFrame = this.cropFrame_;
   function addCropFrame(className) {
     var div = doc.createElement('div');
     div.className = className;
     cropFrame.appendChild(div);
   }
 
@@ skipping 617 matching lines @@
       break;
     case 'bottom':
       this.bounds_.bottom = this.bounds_.top + newHeight;
       break;
     case 'none':
       this.bounds_.top = middle - newHeight / 2;
       this.bounds_.bottom = middle + newHeight / 2;
       break;
   }
 };