Automation API: Get rid of host node and get parent from C++ bindings instead

chrome/renderer/resources/extensions/automation/automation_node.js

Index: chrome/renderer/resources/extensions/automation/automation_node.js
diff --git a/chrome/renderer/resources/extensions/automation/automation_node.js b/chrome/renderer/resources/extensions/automation/automation_node.js
index 15b722570a53cce1a08e750c559672d4226247d3..1f9a44271be13c1e52e03600118e9f1ac07124b1 100644
--- a/chrome/renderer/resources/extensions/automation/automation_node.js
+++ b/chrome/renderer/resources/extensions/automation/automation_node.js
@@ -79,10 +79,11 @@ var GetFocusAffinity = requireNative('automationInternal').GetFocusAffinity;
 /**
  * @param {number} axTreeID The id of the accessibility tree.
  * @param {number} nodeID The id of a node.
- * @return {?number} The id of the node's parent, or undefined if it's the
+ * @return {?Array<number>} An array containing the tree id and node id
+ *    of the node's parent, or undefined if it's the
  *    root of its tree or if the tree or node wasn't found.
  */
-var GetParentID = requireNative('automationInternal').GetParentID;
+var GetParent = requireNative('automationInternal').GetParent;
 
 /**
  * @param {number} axTreeID The id of the accessibility tree.
@@ -242,7 +243,6 @@ var utils = require('utils');
  */
 function AutomationNodeImpl(root) {
   this.rootImpl = root;
-  this.hostNode_ = null;
   this.listeners = {__proto__: null};
 }
 
@@ -254,7 +254,6 @@ AutomationNodeImpl.prototype = {
 
   detach: function() {
     this.rootImpl = null;
-    this.hostNode_ = null;
     this.listeners = {__proto__: null};
   },
 
@@ -265,10 +264,17 @@ AutomationNodeImpl.prototype = {
   get parent() {
     if (!this.rootImpl)
       return undefined;
-    if (this.hostNode_)
-      return this.hostNode_;
-    var parentID = GetParentID(this.treeID, this.id);
-    return this.rootImpl.get(parentID);
+    var parentTreeIDAndNodeID = GetParent(this.treeID, this.id);
+    if (!parentTreeIDAndNodeID)
+      return undefined;
+    var parentTreeID = parentTreeIDAndNodeID[0];
+    var parentNodeID = parentTreeIDAndNodeID[1];
+    if (parentTreeID == this.treeID)
+      return this.rootImpl.get(parentNodeID);
+    var tree = AutomationRootNodeImpl.get(parentTreeID);
+    if (!tree)
+      return undefined;
+    return tree.get(parentNodeID);
   },
 
   get htmlAttributes() {
@@ -495,7 +501,6 @@ AutomationNodeImpl.prototype = {
   },
 
   toString: function() {
-    var parentID = GetParentID(this.treeID, this.id);
     var childTreeID = GetIntAttribute(this.treeID, this.id, 'childTreeId');
     var count = GetChildCount(this.treeID, this.id);
     var childIDs = [];
@@ -507,13 +512,7 @@ AutomationNodeImpl.prototype = {
     var result = 'node id=' + this.id +
         ' role=' + this.role +
         ' state=' + $JSON.stringify(this.state) +
-        ' parentID=' + parentID +
         ' childIds=' + $JSON.stringify(childIDs);
-    if (this.hostNode_) {
-      var hostNodeImpl = privates(this.hostNode_).impl;
-      result += ' host treeID=' + hostNodeImpl.treeID +
-          ' host nodeID=' + hostNodeImpl.id;
-    }
     if (childTreeID)
       result += ' childTreeID=' + childTreeID;
     return result;
@@ -914,13 +913,6 @@ AutomationRootNodeImpl.prototype = {
   treeID: -1,
 
   /**
-   * The parent of this node from a different tree.
-   * @type {?AutomationNode}
-   * @private
-   */
-  hostNode_: null,
-
-  /**
    * A map from id to AutomationNode.
    * @type {Object.<number, AutomationNode>}
    * @private
@@ -1030,10 +1022,6 @@ AutomationRootNodeImpl.prototype = {
     this.detach();
   },
 
-  setHostNode(hostNode) {
-    this.hostNode_ = hostNode;
-  },
-
   onAccessibilityEvent: function(eventParams) {
     var targetNode = this.get(eventParams.targetID);
     if (targetNode) {