[DevTools] Do not toggle tree element if there is a selection.

This prevents the toggling when user just wanted to select text.
Note that simple click usually clears the selection and element will be toggled.

BUG=none

Review-Url: https://codereview.chromium.org/2346873005
Cr-Commit-Position: refs/heads/master@{#419353}

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

@@ -368,7 +368,6 @@ function TreeElement(title, expandable)
     if (title)
         this.title = title;
     this._listItemNode.addEventListener("mousedown", this._handleMouseDown.bind(this), false);
-    this._listItemNode.addEventListener("selectstart", this._treeElementSelectStart.bind(this), false);
     this._listItemNode.addEventListener("click", this._treeElementToggled.bind(this), false);
     this._listItemNode.addEventListener("dblclick", this._handleDoubleClick.bind(this), false);
 
@@ -776,28 +775,13 @@ TreeElement.prototype = {
         this._listItemNode.insertBefore(this._selectionElement, this.listItemElement.firstChild);
     },
 
-    /**
-     * @param {!Event} event
-     */
-    _treeElementSelectStart: function(event)
-    {
-        event.currentTarget._selectionStarted = true;
-    },
-
     /**
      * @param {!Event} event
      */
     _treeElementToggled: function(event)
     {
         var element = event.currentTarget;
-        if (element._selectionStarted) {
-            delete element._selectionStarted;
-            var selection = element.getComponentSelection();
-            if (selection && !selection.isCollapsed && element.isSelfOrAncestor(selection.anchorNode) && element.isSelfOrAncestor(selection.focusNode))
-                return;
-        }
-
-        if (element.treeElement !== this)
+        if (element.treeElement !== this || element.hasSelection())
             return;
 
         var toggleOnClick = this.toggleOnClick && !this.selectable;
@@ -830,8 +814,6 @@ TreeElement.prototype = {
         var element = event.currentTarget;
         if (!element)
             return;
-        delete element._selectionStarted;
-
         if (!this.selectable)
             return;
         if (element.treeElement !== this)