DevTools: Fix illegal argument types in ViewportControl

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 301 matching lines @@
             headElement = this._headSelection.node;
             headOffset = this._headSelection.offset;
         } else {
             if (this._headSelection.item < this._firstVisibleIndex)
                 headElement = this._topGapElement;
             else if (this._headSelection.item > this._lastVisibleIndex)
                 headElement = this._bottomGapElement;
             headOffset = this._selectionIsBackward ? 0 : 1;
         }
 
-        selection.setBaseAndExtent(anchorElement, anchorOffset, headElement, headOffset);
+        selection.setBaseAndExtent(anchorElement || null, anchorOffset, headElement || null, headOffset);

[lushnikov, 2014/06/17 08:15:36]

Can't we initialize anchorElement and headElement with null by default?

[apavlov, 2014/06/17 08:27:18]

Done.

     },
 
     refresh: function()
     {
         if (!this.element.clientHeight)
             return;  // Do nothing for invisible controls.
 
         var itemCount = this._provider.itemCount();
         if (!itemCount) {
             for (var i = 0; i < this._renderedItems.length; ++i)
@@ skipping 99 matching lines @@
      * @param {!Node} container
      * @param {number} offset
      * @return {number}
      */
     _textOffsetInNode: function(itemElement, container, offset)
     {
         if (!offset)
             return 0;
         var chars = 0;
         var node = itemElement;
-        while ((node = node.traverseNextTextNode(true)) && node !== container)
+        while ((node = node.traverseNextTextNode()) && node !== container)
             chars += node.textContent.length;
         return chars + offset;
     },
 
     /**
      * @param {?Event} event
      */
     _onScroll: function(event)
     {
         this.refresh();
@@ skipping 52 matching lines @@
 
     /**
      * @param {number} index
      */
     forceScrollItemToBeLast: function(index)
     {
         this._rebuildCumulativeHeightsIfNeeded();
         this.element.scrollTop = this._cumulativeHeights[index] - this.element.clientHeight;
     }
 }