DevToo: fix JavaScriptBreakpoint checkboxes in Sources panel

Source/devtools/front_end/sources/JavaScriptBreakpointsSidebarPane.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.
 
 /**
  * @constructor
  * @extends {WebInspector.SidebarPane}
  * @param {!WebInspector.BreakpointManager} breakpointManager
  * @param {function(!WebInspector.UISourceCode, number=, number=, boolean=)} showSourceLineDelegate
  */
@@ skipping 57 matching lines @@
     /**
      * @param {!WebInspector.BreakpointManager.Breakpoint} breakpoint
      * @param {!WebInspector.UILocation} uiLocation
      */
     _addBreakpoint: function(breakpoint, uiLocation)
     {
         var element = createElementWithClass("li", "cursor-pointer");
         element.addEventListener("contextmenu", this._breakpointContextMenu.bind(this, breakpoint), true);
         element.addEventListener("click", this._breakpointClicked.bind(this, uiLocation), false);
 
-        var checkbox = createCheckboxLabel(uiLocation.linkText(), breakpoint.enabled());
-        element.appendChild(checkbox);
-        checkbox.addEventListener("click", this._breakpointCheckboxClicked.bind(this, breakpoint), false);
+        var checkboxLabel = createCheckboxLabel(uiLocation.linkText(), breakpoint.enabled());
+        element.appendChild(checkboxLabel);
+        checkboxLabel.addEventListener("click", this._breakpointCheckboxClicked.bind(this, breakpoint), false);
 
         var snippetElement = element.createChild("div", "source-text monospace");
 
         /**
          * @param {?string} content
          */
         function didRequestContent(content)
         {
             var lineNumber = uiLocation.lineNumber
             var columnNumber = uiLocation.columnNumber;
@@ skipping 10 matching lines @@
 
         element._data = uiLocation;
         var currentElement = this.listElement.firstChild;
         while (currentElement) {
             if (currentElement._data && this._compareBreakpoints(currentElement._data, element._data) > 0)
                 break;
             currentElement = currentElement.nextSibling;
         }
         this._addListElement(element, currentElement);
 
-        var breakpointItem = { element: element, checkbox: checkbox };
+        var breakpointItem = { element: element, checkbox: checkboxLabel.checkboxElement };
         this._items.set(breakpoint, breakpointItem);
 
         this.expand();
     },
 
     /**
      * @param {!WebInspector.Event} event
      */
     _breakpointRemoved: function(event)
     {
@@ skipping 120 matching lines @@
         this.listElement.removeChildren();
         if (this.listElement.parentElement) {
             this.element.removeChild(this.listElement);
             this.element.appendChild(this.emptyElement);
         }
         this._items.clear();
     },
 
     __proto__: WebInspector.SidebarPane.prototype
 }