Reland #2: Ensure WebView notifies desktop automation on creation, destruction, and change Original

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

Index: chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_util.js
diff --git a/chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_util.js b/chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_util.js
index d5d9956f345141a1a4dd2edde5f88132d37f01f4..16f7506bb8105264199e695126d823c3a9de0ab6 100644
--- a/chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_util.js
+++ b/chrome/browser/resources/chromeos/chromevox/cvox2/background/automation_util.js
@@ -88,8 +88,12 @@ AutomationUtil.findNextSubtree = function(cur, dir) {
   while (cur) {
     var next = dir == Dir.BACKWARD ?
         cur.previousSibling : cur.nextSibling;
+    if (!AutomationUtil.isInSameTree(cur, next))
+      return null;
     if (next)
       return next;
+    if (!AutomationUtil.isInSameTree(cur, cur.parent))
+      return null;
     cur = cur.parent;
   }
 };
@@ -164,6 +168,10 @@ AutomationUtil.getAncestors = function(node) {
   var candidate = node;
   while (candidate) {
     ret.push(candidate);
+
+    if (!AutomationUtil.isInSameTree(candidate, candidate.parent))
+      break;
+
     candidate = candidate.parent;
   }
   return ret.reverse();
@@ -226,4 +234,17 @@ AutomationUtil.getDirection = function(nodeA, nodeB) {
   return divA.indexInParent <= divB.indexInParent ? Dir.FORWARD : Dir.BACKWARD;
 };
 
+/**
+ * Determines whether the two given nodes come from the same tree source.
+ * @param {AutomationNode} a
+ * @param {AutomationNode} b
+ * @return {boolean}
+ */
+AutomationUtil.isInSameTree = function(a, b) {
+  if (!a || !b)
+    return true;
+
+  return a.root === b.root;
+};
+
 });  // goog.scope