DevTools: Fix regression that slows down "Goto Source" dialog

Source/devtools/front_end/console/ConsoleView.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * 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 142 matching lines @@
     /**
      * @param {number} index
      * @return {?WebInspector.ViewportElement}
      */
     itemElement: function(index)
     {
         return this._visibleViewMessages[index];
     },
 
     /**
+     * @param {number} index
+     * @return {number}
+     */
+    fastHeight: function(index)
+    {
+        return this._visibleViewMessages[index].fastHeight();
+    },
+
+    /**
      * @param {!WebInspector.Target} target
      */
     targetAdded: function(target)
     {
         /**
          * @param {!WebInspector.ConsoleMessage} message
          * @this {WebInspector.ConsoleView}
          */
         function appendMessage(message)
         {
@@ skipping 955 matching lines @@
 WebInspector.ConsoleView.ShowConsoleActionDelegate.prototype = {
     /**
      * @return {boolean}
      */
     handleAction: function()
     {
         WebInspector.console.show();
         return true;
     }
 }