[DevTools] Remove remaining usages of global properties.

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 264 matching lines @@
         return new Constraints(this.minimum.addHeight(value), this.preferred.addHeight(value));
     return new Constraints(this.minimum.addHeight(value.minimum), this.preferred.addHeight(value.preferred));
 }
 
 /**
  * @param {?Element=} containerElement
  * @return {!Size}
  */
 Element.prototype.measurePreferredSize = function(containerElement)
 {
-    containerElement = containerElement || document.body;
+    containerElement = containerElement || this.ownerDocument.body;
     containerElement.appendChild(this);
     var fakingComponentRoot = false;
     if (!this.classList.contains("component-root")) {
         fakingComponentRoot = true;
         this.classList.add("component-root");
     }
     this.positionAt(0, 0);
     var result = new Size(this.offsetWidth, this.offsetHeight);
     this.positionAt(undefined, undefined);
     this.remove();
@@ skipping 97 matching lines @@
     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}
+ * @suppressGlobalPropertiesCheck
  */
 function createElement(tagName)
 {
     return document.createElement(tagName);
 }
 
 /**
  * @param {number|string} data
  * @return {!Text}
+ * @suppressGlobalPropertiesCheck
  */
 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}
+ * @suppressGlobalPropertiesCheck
  */
 function createElementWithClass(elementName, className)
 {
     return document.createElementWithClass(elementName, className);
 }
 
 /**
  * @return {!DocumentFragment}
+ * @suppressGlobalPropertiesCheck
  */
 function createDocumentFragment()
 {
     return document.createDocumentFragment();
 }
 
 /**
  * @param {string} elementName
  * @param {string=} className
  * @return {!Element}
@@ skipping 409 matching lines @@
  */
 function isEnterKey(event) {
     // Check if in IME.
     return event.keyCode !== 229 && event.keyIdentifier === "Enter";
 }
 
 function consumeEvent(e)
 {
     e.consume();
 }