DevTools: Fix an exception on adding watch expression.

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 615 matching lines @@
     if (typeof this._title === 'string')
       return this._title;
     return this._title.textContent;
   }
 
   /**
    * @param {!UI.InplaceEditor.Config} editingConfig
    */
   startEditingTitle(editingConfig) {
     UI.InplaceEditor.startEditing(this._titleElement, editingConfig);
-    this.treeOutline._shadowRoot.getSelection().setBaseAndExtent(this._titleElement, 0, this._titleElement, 1);
+    this.treeOutline._shadowRoot.getSelection().selectAllChildren(this._titleElement);
   }
 
   /**
    * @param {!Array<!UI.Icon>} icons
    */
   setLeadingIcons(icons) {
     if (!this._leadingIconsElement && !icons.length)
       return;
     if (!this._leadingIconsElement) {
       this._leadingIconsElement = createElementWithClass('div', 'leading-icons');
@@ skipping 568 matching lines @@
 UI.TreeElement._ArrowToggleWidth = 10;
 
 (function() {
   var img = new Image();
   if (window.devicePixelRatio > 1)
     img.src = 'Images/treeoutlineTriangles_2x.png';
   else
     img.src = 'Images/treeoutlineTriangles.png';
   UI.TreeElement._imagePreload = img;
 })();