Make ChromeVox cursor robust to deleted nodes

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

Index: chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
diff --git a/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js b/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
index b0c3985cf3393046d40f2a915132a80aa1e78e53..5ff3151313325eb817d0ece9cb0e6a519e86745c 100644
--- a/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
+++ b/chrome/browser/resources/chromeos/chromevox/cvox2/background/background.js
@@ -750,22 +750,24 @@ Background.prototype = {
     }
 
     if (pred) {
-      var node = AutomationUtil.findNextNode(
-          current.getBound(dir).node, dir, pred, {skipInitialAncestry: true});
-
-      if (node) {
-        node = AutomationUtil.findNodePre(
-            node, dir, AutomationPredicate.element) || node;
-      }
+      var bound = current.getBound(dir).node;
+      if (bound) {
+        var node = AutomationUtil.findNextNode(
+            bound, dir, pred, {skipInitialAncestry: true});
+        if (node) {
+          node = AutomationUtil.findNodePre(
+              node, dir, AutomationPredicate.element) || node;
+        }
 
-      if (node) {
-        current = cursors.Range.fromNode(node);
-      } else {
-        if (predErrorMsg) {
-          cvox.ChromeVox.tts.speak(Msgs.getMsg(predErrorMsg),
-                                   cvox.QueueMode.FLUSH);
+        if (node) {
+          current = cursors.Range.fromNode(node);
+        } else {
+          if (predErrorMsg) {
+            cvox.ChromeVox.tts.speak(Msgs.getMsg(predErrorMsg),
+                                     cvox.QueueMode.FLUSH);
+          }
+          return false;
         }
-        return false;
       }
     }