[DevTools] Replace usages of document with custom functions.

Source/devtools/front_end/ui/DOMExtension.js

 /*
  * Copyright (C) 2007 Apple Inc.  All rights reserved.
  * Copyright (C) 2012 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.
@@ skipping 380 matching lines @@
 Element.prototype.isInsertionCaretInside = function()
 {
     var selection = window.getSelection();
     if (!selection.rangeCount || !selection.isCollapsed)
         return false;
     var selectionRange = selection.getRangeAt(0);
     return selectionRange.startContainer.isSelfOrDescendant(this);
 }
 
 /**
+ * @param {string} tagName
+ * @return {!Element}
+ */
+function createElement(tagName)
+{
+    return document.createElement(tagName);
+}
+
+/**
+ * @param {number|string} data
+ * @return {!Text}
+ */
+function createTextNode(data)
+{
+    return document.createTextNode(data);
+}
+
+/**
  * @param {string} elementName
  * @param {string=} className
  * @return {!Element}
  */
 Document.prototype.createElementWithClass = function(elementName, className)
 {
     var element = this.createElement(elementName);
     if (className)
         element.className = className;
     return element;
 }
 
 /**
  * @param {string} elementName
  * @param {string=} className
  * @return {!Element}
  */
+function createElementWithClass(elementName, className)
+{
+    return document.createElementWithClass(elementName, className);
+}
+
+/**
+ * @return {!DocumentFragment}
+ */
+function createDocumentFragment()
+{
+    return document.createDocumentFragment();
+}
+
+/**
+ * @param {string} elementName
+ * @param {string=} className
+ * @return {!Element}
+ */
 Element.prototype.createChild = function(elementName, className)
 {
     var element = this.ownerDocument.createElementWithClass(elementName, className);
     this.appendChild(element);
     return element;
 }
 
 DocumentFragment.prototype.createChild = Element.prototype.createChild;
 
 /**
@@ skipping 389 matching lines @@
  */
 function isEnterKey(event) {
     // Check if in IME.
     return event.keyCode !== 229 && event.keyIdentifier === "Enter";
 }
 
 function consumeEvent(e)
 {
     e.consume();
 }