Revert of DevTools: cleanup treeoutline expand logic

third_party/WebKit/Source/devtools/front_end/ui/treeoutline.js

 /*
  * Copyright (C) 2007 Apple 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.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 506 matching lines @@
             this.treeOutline._bindTreeElement(current);
         child.onattach();
         child._ensureSelection();
         if (this.treeOutline)
             this.treeOutline.dispatchEventToListeners(TreeOutline.Events.ElementAttached, child);
         var nextSibling = child.nextSibling ? child.nextSibling._listItemNode : null;
         this._childrenListNode.insertBefore(child._listItemNode, nextSibling);
         this._childrenListNode.insertBefore(child._childrenListNode, nextSibling);
         if (child.selected)
             child.select();
+        if (child.expanded)
+            child.expand();
     },
 
     /**
      * @param {number} childIndex
      */
     removeChildAtIndex: function(childIndex)
     {
         if (childIndex < 0 || childIndex >= this._children.length)
             throw "childIndex out of range";
 
@@ skipping 337 matching lines @@
         var item = this;
         while (item) {
             if (item.expanded)
                 item.collapse();
             item = item.traverseNextTreeElement(false, this, true);
         }
     },
 
     expand: function()
     {
-        if (!this._expandable || this.expanded)
+        if (!this._expandable || (this.expanded && this._children))
             return;
 
         // Set this before onpopulate. Since onpopulate can add elements, this makes
         // sure the expanded flag is true before calling those functions. This prevents the possibility
         // of an infinite loop if onpopulate were to call expand.
 
         this.expanded = true;
 
         this._populateIfNeeded();
         this._listItemNode.classList.add("expanded");
@@ skipping 266 matching lines @@
     isEventWithinDisclosureTriangle: function(event)
     {
         // FIXME: We should not use getComputedStyle(). For that we need to get rid of using ::before for disclosure triangle. (http://webk.it/74446)
         var paddingLeftValue = window.getComputedStyle(this._listItemNode).paddingLeft;
         console.assert(paddingLeftValue.endsWith("px"));
         var computedLeftPadding = parseFloat(paddingLeftValue);
         var left = this._listItemNode.totalOffsetLeft() + computedLeftPadding;
         return event.pageX >= left && event.pageX <= left + TreeElement._ArrowToggleWidth && this._expandable;
     }
 }