Allow tree walker to escape roots

chrome/browser/resources/chromeos/chromevox/cvox2/background/tree_walker.js

 // Copyright 2015 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.
 
 /**
  * @fileoverview A tree walker over the automation tree.
  */
 
 goog.provide('AutomationTreeWalker');
 goog.provide('AutomationTreeWalkerPhase');
@@ skipping 160 matching lines @@
 
       if (!this.skipInitialSubtree_ ||
           this.phase != AutomationTreeWalkerPhase.DESCENDANT) {
         this.node_ = node.firstChild;
         return;
       }
     }
 
     var searchNode = node;
     while (searchNode) {
-      // We have crossed out of the initial node's subtree.
+      // We have crossed out of the initial node's subtree for either a
+      // sibling or parent move.
       if (searchNode == this.initialNode_)
         this.phase_ = AutomationTreeWalkerPhase.OTHER;
 
       if (searchNode.nextSibling) {
         this.node_ = searchNode.nextSibling;
         return;
       }
-      if (searchNode.parent && this.rootPred_(searchNode.parent))
+
+      // Update the phase based on the parent if needed since we may exit below.
+      if (searchNode.parent == this.initialNode_)
+        this.phase_ = AutomationTreeWalkerPhase.OTHER;
+
+      // Exit if we encounter a root-like node and are not searching descendants
+      // of the initial node.
+      if (searchNode.parent &&
+          this.rootPred_(searchNode.parent) &&
+          this.phase_ != AutomationTreeWalkerPhase.DESCENDANT)
         break;
 
       searchNode = searchNode.parent;
     }
     this.node_ = null;
   },
 
   /**
    * @param {!chrome.automation.AutomationNode} node
    * @private
    */
   backward_: function(node) {
     if (node.previousSibling) {
       this.phase_ = AutomationTreeWalkerPhase.OTHER;
       node = node.previousSibling;
 
       while (!this.leafPred_(node) && node.lastChild)
         node = node.lastChild;
 
       this.node_ = node;
       return;
     }
     if (node.parent && this.backwardAncestor_ == node.parent) {
       this.phase_ = AutomationTreeWalkerPhase.ANCESTOR;
       this.backwardAncestor_ = node.parent.parent;
     }
     this.node_ = node.parent;
   }
 };