[DevTools] Do not inherit SDK.DOMNode from SDK.SDKObject

third_party/WebKit/Source/devtools/front_end/elements/ClassesPaneWidget.js

 // Copyright (c) 2015 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.
 /**
  * @unrestricted
  */
 Elements.ClassesPaneWidget = class extends UI.Widget {
   constructor() {
     super();
     this.element.className = 'styles-element-classes-pane';
@@ skipping 208 matching lines @@
 
   /**
    * @param {!SDK.DOMNode} selectedNode
    * @return {!Promise.<!Array.<string>>}
    */
   _getClassNames(selectedNode) {
     var promises = [];
     var completions = new Set();
     this._selectedFrameId = selectedNode.frameId();
 
-    var cssModel = SDK.CSSModel.fromNode(selectedNode);
+    var cssModel = selectedNode.domModel().cssModel();
     var allStyleSheets = cssModel.allStyleSheets();
     for (var stylesheet of allStyleSheets) {
       if (stylesheet.frameId !== this._selectedFrameId)
         continue;
       var cssPromise = cssModel.classNamesPromise(stylesheet.id).then(classes => completions.addAll(classes));
       promises.push(cssPromise);
     }
 
     var domPromise = selectedNode.domModel()
                          .classNamesPromise(selectedNode.ownerDocument.id)
@@ skipping 19 matching lines @@
     if (!this._classNamesPromise || this._selectedFrameId !== selectedNode.frameId())
       this._classNamesPromise = this._getClassNames(selectedNode);
 
     return this._classNamesPromise.then(completions => {
       if (prefix[0] === '.')
         completions = completions.map(value => '.' + value);
       return completions.filter(value => value.startsWith(prefix)).map(completion => ({text: completion}));
     });
   }
 };