DevTools: Fix an exception on adding watch expression.

third_party/WebKit/Source/devtools/front_end/elements/ElementsTreeElement.js

 /*
  * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2008 Matt Lilek <webkit@mattlilek.com>
  * 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
@@ skipping 621 matching lines @@
     function postKeyDownFinishHandler(event) {
       UI.handleElementValueModifications(event, attribute);
       return '';
     }
 
     if (!attributeValueElement.textContent.asParsedURL())
       config.setPostKeydownFinishHandler(postKeyDownFinishHandler);
 
     this._editing = UI.InplaceEditor.startEditing(attribute, config);
 
-    this.listItemElement.getComponentSelection().setBaseAndExtent(elementForSelection, 0, elementForSelection, 1);
+    this.listItemElement.getComponentSelection().selectAllChildren(elementForSelection);
 
     return true;
   }
 
   /**
    * @param {!Element} textNodeElement
    */
   _startEditingTextNode(textNodeElement) {
     if (UI.isBeingEdited(textNodeElement))
       return true;
 
     var textNode = this._node;
     // We only show text nodes inline in elements if the element only
     // has a single child, and that child is a text node.
     if (textNode.nodeType() === Node.ELEMENT_NODE && textNode.firstChild)
       textNode = textNode.firstChild;
 
     var container = textNodeElement.enclosingNodeOrSelfWithClass('webkit-html-text-node');
     if (container)
       container.textContent = textNode.nodeValue();  // Strip the CSS or JS highlighting if present.
     var config = new UI.InplaceEditor.Config(
         this._textNodeEditingCommitted.bind(this, textNode), this._editingCancelled.bind(this));
     this._editing = UI.InplaceEditor.startEditing(textNodeElement, config);
-    this.listItemElement.getComponentSelection().setBaseAndExtent(textNodeElement, 0, textNodeElement, 1);
+    this.listItemElement.getComponentSelection().selectAllChildren(textNodeElement);
 
     return true;
   }
 
   /**
    * @param {!Element=} tagNameElement
    */
   _startEditingTagName(tagNameElement) {
     if (!tagNameElement) {
       tagNameElement = this.listItemElement.getElementsByClassName('webkit-html-tag-name')[0];
@@ skipping 33 matching lines @@
      */
     function editingCancelled() {
       tagNameElement.removeEventListener('keyup', keyupListener, false);
       this._editingCancelled.apply(this, arguments);
     }
 
     tagNameElement.addEventListener('keyup', keyupListener, false);
 
     var config = new UI.InplaceEditor.Config(editingComitted.bind(this), editingCancelled.bind(this), tagName);
     this._editing = UI.InplaceEditor.startEditing(tagNameElement, config);
-    this.listItemElement.getComponentSelection().setBaseAndExtent(tagNameElement, 0, tagNameElement, 1);
+    this.listItemElement.getComponentSelection().selectAllChildren(tagNameElement);
     return true;
   }
 
   /**
    * @param {function(string, string)} commitCallback
    * @param {function()} disposeCallback
    * @param {?Protocol.Error} error
    * @param {string} initialValue
    */
   _startEditingAsHTML(commitCallback, disposeCallback, error, initialValue) {
@@ skipping 835 matching lines @@
 
 // A union of HTML4 and HTML5-Draft elements that explicitly
 // or implicitly (for HTML5) forbid the closing tag.
 Elements.ElementsTreeElement.ForbiddenClosingTagElements = new Set([
   'area', 'base',  'basefont', 'br',   'canvas',   'col',  'command', 'embed',  'frame', 'hr',
   'img',  'input', 'keygen',   'link', 'menuitem', 'meta', 'param',   'source', 'track', 'wbr'
 ]);
 
 // These tags we do not allow editing their tag name.
 Elements.ElementsTreeElement.EditTagBlacklist = new Set(['html', 'head', 'body']);