[File Manager] Support HiDPI images in action picker and default action picker

chrome/browser/resources/file_manager/js/file_manager.js

 // Copyright (c) 2012 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.
 
 /**
  * FileManager constructor.
  *
  * FileManager objects encapsulate the functionality of the file selector
  * dialogs, as well as the full screen file manager application (though the
  * latter is not yet implemented).
@@ skipping 2520 matching lines @@
         if (match) {
           var ext = match[1].toUpperCase();
           if (extensions.indexOf(ext) == -1) {
             extensions.push(ext);
           }
         }
       }
 
       var format = '';
 
-      if (extensions.length != 1) {
+      if (extensions.length == 1) {
         format = extensions[0];
       }
 
       // Change default was clicked. We should open "change default" dialog.
       this.defaultTaskPicker.show(
           strf('CHANGE_DEFAULT_CAPTION', format),
           event.item.items, event.item.defaultIdx,
           this.onDefaultTaskDone_.bind(this));
     }
   };
@@ skipping 1578 matching lines @@
       this.defaultActionMenuItem_.taskId = taskItem.taskId;
     }
 
     var defaultActionSeparator =
         this.dialogDom_.querySelector('#default-action-separator');
 
     this.defaultActionMenuItem_.hidden = !taskItem;
     defaultActionSeparator.hidden = !taskItem;
   }
 })();