[DevTools] Migrate checkbox label to a proper web component

third_party/WebKit/Source/devtools/front_end/elements/ElementStatePaneWidget.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.ElementStatePaneWidget = class extends UI.Widget {
   constructor() {
     super();
     this.element.className = 'styles-element-state-pane';
@@ skipping 12 matching lines @@
         return;
       SDK.CSSModel.fromNode(node).forcePseudoState(node, event.target.state, event.target.checked);
     }
 
     /**
      * @param {string} state
      * @return {!Element}
      */
     function createCheckbox(state) {
       var td = createElement('td');
-      var label = UI.createCheckboxLabel(':' + state);
+      var label = UI.CheckboxLabel.create(':' + state);
       var input = label.checkboxElement;
       input.state = state;
       input.addEventListener('click', clickListener, false);
       inputs.push(input);
       td.appendChild(label);
       return td;
     }
 
     var tr = table.createChild('tr');
     tr.appendChild(createCheckbox.call(null, 'active'));
@@ skipping 69 matching lines @@
   }
 
   /**
    * @override
    * @return {!UI.ToolbarItem}
    */
   item() {
     return this._button;
   }
 };