DevTools: Reduce code via using document.createElementWithClass and document.createChild.

Source/devtools/front_end/ui/Checkbox.js

 /*
  * Copyright (C) 2010 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 13 matching lines @@
  */
 
 /**
  * @constructor
  * @param {string} label
  * @param {string} className
  * @param {string=} tooltip
  */
 WebInspector.Checkbox = function(label, className, tooltip)
 {
-    this.element = document.createElement('label');
-    this._inputElement = document.createElement('input');
+    this.element = document.createElementWithClass("label", className);
+    this._inputElement = this.element.createChild("input");
     this._inputElement.type = "checkbox";
-
-    this.element.className = className;
-    this.element.appendChild(this._inputElement);
-    this.element.appendChild(document.createTextNode(label));
+    this.element.createTextChild(label);
     if (tooltip)
         this.element.title = tooltip;
 }
 
 WebInspector.Checkbox.prototype = {
     set checked(checked)
     {
         this._inputElement.checked = checked;
     },
 
     get checked()
     {
         return this._inputElement.checked;
     },
 
     addEventListener: function(listener)
     {
         function listenerWrapper(event)
         {
             if (listener)
                 listener(event);
             event.consume();
             return true;
         }
 
         this._inputElement.addEventListener("click", listenerWrapper, false);
         this.element.addEventListener("click", listenerWrapper, false);
     }
 }