Don't sync DOM selection for root a11y node

third_party/WebKit/Source/devtools/front_end/accessibility/AXTreePane.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 /**
  * @unrestricted
  */
 Accessibility.AXTreePane = class extends Accessibility.AccessibilitySubPane {
-  constructor() {
+  /**
+   * @param {!Accessibility.AccessibilitySidebarView} axSidebarView
+   */
+  constructor(axSidebarView) {
     super(Common.UIString('Accessibility Tree'));
 
+    this._axSidebarView = axSidebarView;
     this._treeOutline = this.createTreeOutline();
 
     this.element.classList.add('accessibility-computed');
 
     this._expandedNodes = new Set();
   }
 
   /**
    * @param {?Accessibility.AccessibilityNode} axNode
    * @override
@@ skipping 49 matching lines @@
     }
 
     inspectedNodeTreeElement.selectable = true;
     inspectedNodeTreeElement.select(!this._selectedByUser /* omitFocus */, false);
     if (this.isExpanded(axNode.backendDOMNodeId()))
       inspectedNodeTreeElement.expand();
     this.clearSelectedByUser();
   }
 
   /**
+   * @param {!Accessibility.AccessibilityNode} axNode
+   */
+  setSelectedNode(axNode) {
+    if (axNode.parentNode()) {
+      Common.Revealer.reveal(axNode.deferredDOMNode());
+    } else {
+      // Only set the node for the accessibility panel, not the Elements tree.
+      var axSidebarView = this._axSidebarView;
+      function nodeResolved(node) {

[dgozman, 2017/01/04 00:11:05]

Can use arrow function instead.

[aboxhall, 2017/01/04 01:06:10]

Done.

+        axSidebarView.setNode(node);
+      }
+      axNode.deferredDOMNode().resolve(nodeResolved);
+    }
+  }
+
+  /**
    * @param {boolean} selectedByUser
    */
   setSelectedByUser(selectedByUser) {
     this._selectedByUser = true;
   }
 
   clearSelectedByUser() {
     delete this._selectedByUser;
   }
 
@@ skipping 40 matching lines @@
 
     this.element = UI.Icon.create('smallicon-arrow-in-circle', 'inspect-dom-node');
     this.element.addEventListener('mousedown', this._handleMouseDown.bind(this));
   }
 
   /**
    * @param {!Event} event
    */
   _handleMouseDown(event) {
     this._treePane.setSelectedByUser(true);
-    Common.Revealer.reveal(this._axNode.deferredDOMNode());
+    this._treePane.setSelectedNode(this._axNode);

[dgozman, 2017/01/04 00:11:05]

Does it make sense to merge setSelectedByUser and setSelectedNode now?

[aboxhall, 2017/01/04 01:06:10]

I wanted to leave them separate, since it's plausible that setSelectedNode may
be called from a context which is not user-initiated.

   }
 };
 
 /**
  * @unrestricted
  */
 Accessibility.AXNodeTreeElement = class extends UI.TreeElement {
   /**
    * @param {!Accessibility.AccessibilityNode} axNode
    * @param {!Accessibility.AXTreePane} treePane
@@ skipping 47 matching lines @@
    * @param {!Event} event
    * @return {boolean}
    */
   ondblclick(event) {
     this.inspectDOMNode();
     return true;
   }
 
   inspectDOMNode() {
     this._treePane.setSelectedByUser(true);
-    Common.Revealer.reveal(this._axNode.deferredDOMNode());
+    this._treePane.setSelectedNode(this._axNode);
   }
 
   /**
    * @override
    */
   onattach() {
     this._update();
   }
 
   _update() {
@@ skipping 190 matching lines @@
         continue;
       }
       siblingTreeElement = new Accessibility.AXNodeTreeElement(sibling, this._treePane);
       if (foundInspectedNode)
         this.appendChild(siblingTreeElement);
       else
         this.insertChild(siblingTreeElement, nextIndex++);
     }
   }
 };