[DevTools] Replace usages of document with custom functions.

Source/devtools/front_end/ui/ViewportControl.js

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 /**
  * @constructor
  * @param {!WebInspector.ViewportControl.Provider} provider
  */
 WebInspector.ViewportControl = function(provider)
 {
-    this.element = document.createElement("div");
+    this.element = createElement("div");
     this.element.style.overflow = "auto";
     this._topGapElement = this.element.createChild("div", "viewport-control-gap-element");
     this._topGapElement.textContent = ".";
     this._topGapElement.style.height = "0px";
     this._contentElement = this.element.createChild("div");
     this._bottomGapElement = this.element.createChild("div", "viewport-control-gap-element");
     this._bottomGapElement.textContent = ".";
     this._bottomGapElement.style.height = "0px";
 
     this._provider = provider;
@@ skipping 553 matching lines @@
 
     /**
      * @return {number}
      */
     _visibleHeight: function()
     {
         // Use offsetHeight instead of clientHeight to avoid being affected by horizontal scroll.
         return this.element.offsetHeight;
     }
 }