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

chrome/browser/resources/file_manager/js/combobutton.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.
 
 /**
  * @fileoverview This implements a combobutton control.
  */
 
 cr.define('cr.ui', function() {
   /**
@@ skipping 13 matching lines @@
     /**
      * Truncates drop-down list.
      */
     clear: function() {
       this.menu.clear();
       this.multiple = false;
     },
 
     addDropDownItem: function(item) {
       this.multiple = true;
-      this.menu.addMenuItem(item).data = item;
+      var menuitem = this.menu.addMenuItem(item);
+      menuitem.data = item;
+      if (item.iconType) {
+        menuitem.style.backgroundImage = '';
+        menuitem.setAttribute('file-type-icon', item.iconType);
+      }
     },
 
     /**
      * Adds separator to drop-down list.
      */
     addSeparator: function() {
       this.menu.addSeparator();
     },
 
     /**
      * Default item to fire on combobox click
      */
     get defaultItem() {
       return this.defaultItem_;
     },
     set defaultItem(defaultItem) {
       this.defaultItem_ = defaultItem;
-      if (defaultItem.label) {
-        this.labelNode_.textContent = defaultItem.label;
+
+      this.actionNode_.textContent = defaultItem.label || '';
+
+      if (defaultItem.iconType) {
+        this.actionNode_.style.backgroundImage = '';
+        this.actionNode_.setAttribute('file-type-icon', defaultItem.iconType);
+      } else if (defaultItem.iconUrl) {
+        this.actionNode_.style.backgroundImage =
+            'url(' + defaultItem.iconUrl + ')';
       } else {
-        this.labelNode_.textContent = '';
-      }
-
-      if (defaultItem.iconUrl) {
-        this.iconNode_.src = defaultItem.iconUrl;
-      } else {
-        this.iconNode_.src = '';
+        this.actionNode_.style.backgroundImage = '';
       }
     },
 
     /**
      * Initializes the element.
      */
     decorate: function() {
       cr.ui.MenuButton.prototype.decorate.call(this);
 
       this.classList.add('combobutton');
 
-      this.iconNode_ = this.ownerDocument.createElement('img');
-      this.appendChild(this.iconNode_);
-
-      this.labelNode_ = this.ownerDocument.createElement('span');
-      this.appendChild(this.labelNode_);
+      this.actionNode_ = this.ownerDocument.createElement('div');
+      this.actionNode_.classList.add('action');
+      this.appendChild(this.actionNode_);
 
       var triggerIcon = this.ownerDocument.createElement('span');
       triggerIcon.className = 'disclosureindicator';
       this.trigger_ = this.ownerDocument.createElement('div');
+      this.trigger_.classList.add('trigger');
       this.trigger_.appendChild(triggerIcon);
 
       this.appendChild(this.trigger_);
 
       this.addEventListener('click', this.handleButtonClick_.bind(this));
 
       this.trigger_.addEventListener('click',
           this.handleTriggerClicked_.bind(this));
 
       this.menu.addEventListener('activate',
@@ skipping 42 matching lines @@
     }
   };
 
   cr.defineProperty(ComboButton, 'disabled', cr.PropertyKind.BOOL_ATTR);
   cr.defineProperty(ComboButton, 'multiple', cr.PropertyKind.BOOL_ATTR);
 
   return {
     ComboButton: ComboButton
   };
 });