Turn on verbose flag for compiling file_manager.

ui/file_manager/gallery/js/image_editor/image_transform.js

Index: ui/file_manager/gallery/js/image_editor/image_transform.js
diff --git a/ui/file_manager/gallery/js/image_editor/image_transform.js b/ui/file_manager/gallery/js/image_editor/image_transform.js
index 47d9110dea1ac46e715e2ffd62c01999d1a6523a..f3ffd425489478f1e355df543c9cf58c981e8712 100644
--- a/ui/file_manager/gallery/js/image_editor/image_transform.js
+++ b/ui/file_manager/gallery/js/image_editor/image_transform.js
@@ -82,31 +82,33 @@ ImageEditor.Mode.Crop.prototype.setUp = function() {
   var container = this.getImageView().container_;
   var doc = container.ownerDocument;
 
-  this.domOverlay_ = doc.createElement('div');
+  this.domOverlay_ = assertInstanceof(doc.createElement('div'), HTMLDivElement);

[Dan Beam, 2015/10/16 07:20:47]

why do these need to be HTMLDivElement rather than HTMLElement?  do you use
this.domOverlay_.align somewhere?

[fukino, 2015/10/19 09:55:14]

As we call createElement('div'), we expect the returned element is
HTMLDivElement. In general, should we use HTMLElement as long as we don't touch
specific properties of descendent classes.

[Dan Beam, 2015/10/20 00:33:37]

yes, i understand.  HTMLDivElement#align is the /only/ thing that <div> has that
HTMLElement doesn't.  that's why I ask.

these should all be HTMLElement.

https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

   this.domOverlay_.className = 'crop-overlay';
   container.appendChild(this.domOverlay_);
 
-  this.shadowTop_ = doc.createElement('div');
+  this.shadowTop_ = assertInstanceof(doc.createElement('div'), HTMLDivElement);
   this.shadowTop_.className = 'shadow';
   this.domOverlay_.appendChild(this.shadowTop_);
 
-  this.middleBox_ = doc.createElement('div');
+  this.middleBox_ = assertInstanceof(doc.createElement('div'), HTMLDivElement);
   this.middleBox_.className = 'middle-box';
   this.domOverlay_.appendChild(this.middleBox_);
 
-  this.shadowLeft_ = doc.createElement('div');
+  this.shadowLeft_ = assertInstanceof(doc.createElement('div'), HTMLDivElement);
   this.shadowLeft_.className = 'shadow';
   this.middleBox_.appendChild(this.shadowLeft_);
 
-  this.cropFrame_ = doc.createElement('div');
+  this.cropFrame_ = assertInstanceof(doc.createElement('div'), HTMLDivElement);
   this.cropFrame_.className = 'crop-frame';
   this.middleBox_.appendChild(this.cropFrame_);
 
-  this.shadowRight_ = doc.createElement('div');
+  this.shadowRight_ = assertInstanceof(doc.createElement('div'),
+                                       HTMLDivElement);
   this.shadowRight_.className = 'shadow';
   this.middleBox_.appendChild(this.shadowRight_);
 
-  this.shadowBottom_ = doc.createElement('div');
+  this.shadowBottom_ = assertInstanceof(doc.createElement('div'),
+                                        HTMLDivElement);
   this.shadowBottom_.className = 'shadow';
   this.domOverlay_.appendChild(this.shadowBottom_);