Fix some ChromeVox Closure compiler errors.

chrome/browser/resources/chromeos/chromevox/common/description_util.js

 // Copyright 2014 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 utility class for building NavDescriptions from the dom.
  */
 
 
 goog.provide('cvox.DescriptionUtil');
@@ skipping 283 matching lines @@
     prevNode = node;
     node = curSel.start.node;
   }
 
   return descriptions;
 };
 
 /**
  * Returns the full descriptions of the child nodes that would be gotten by an
  * object walker.
- * @param {?Element} prevnode The previous element if there is one.
- * @param {!Element} node The target element.
+ * @param {?Node} prevnode The previous element if there is one.
+ * @param {!Node} node The target element.
  * @return {!Array<!cvox.NavDescription>} The descriptions.
  */
 cvox.DescriptionUtil.getFullDescriptionsFromChildren =
     function(prevnode, node) {
   var descriptions = [];
   if (!node) {
     return descriptions;
   }
   var desc;
   if (cvox.DomUtil.isLeafNode(node)) {
     var ancestors;
     if (prevnode) {
       ancestors = cvox.DomUtil.getUniqueAncestors(prevnode, node);
     } else {
       ancestors = new Array();
       ancestors.push(node);
     }
     desc = cvox.DescriptionUtil.getDescriptionFromAncestors(
         ancestors, true, cvox.ChromeVox.verbosity);
     descriptions.push(desc);
     return descriptions;
   }
   var originalNode = node;
   var curSel = cvox.CursorSelection.fromNode(node);
   if (!curSel) {
     return descriptions;
   }
-  node = cvox.DescriptionUtil.subWalker_.sync(curSel).start.node;
-  curSel = cvox.CursorSelection.fromNode(node);
+  var newNode = cvox.DescriptionUtil.subWalker_.sync(curSel).start.node;
+  curSel = cvox.CursorSelection.fromNode(newNode);
   if (!curSel) {
     return descriptions;
   }
-  while (cvox.DomUtil.isDescendantOfNode(node, originalNode)) {
+  while (newNode && cvox.DomUtil.isDescendantOfNode(newNode, originalNode)) {
     descriptions = descriptions.concat(
-        cvox.DescriptionUtil.getFullDescriptionsFromChildren(prevnode, node));
+        cvox.DescriptionUtil.getFullDescriptionsFromChildren(
+            prevnode, newNode));
     curSel = cvox.DescriptionUtil.subWalker_.next(curSel);
     if (!curSel) {
       break;
     }
     curSel = /** @type {!cvox.CursorSelection} */ (curSel);
-    prevnode = node;
-    node = curSel.start.node;
+    prevnode = newNode;
+    newNode = curSel.start.node;
   }
   return descriptions;
 };
 
 
 /**
  * Modify the descriptions to say that it is a collection.
  * @param {Array<cvox.NavDescription>} descriptions The descriptions.
  * @private
  */
@@ skipping 86 matching lines @@
         return true;
     }
     return cvox.AriaUtil.isLandmark(node);
   });
 };
 
 
 // TODO(sorge): Bad naming...this thing returns *multiple* descriptions.
 /**
  * Generates a description for a math node.
- * @param {!Node} node The given node.
+ * @param {Node} node The given node.
  * @return {!Array<cvox.NavDescription>} A list of Navigation descriptions.
  */
 cvox.DescriptionUtil.getMathDescription = function(node) {
+  if (!node) {
+    return [];
+  }
   // TODO (sorge) This function should evantually be removed. Descriptions
   //     should come directly from the speech rule engine, taking information on
   //     verbosity etc. into account.
   var speechEngine = cvox.SpeechRuleEngine.getInstance();
   var traverse = cvox.TraverseMath.getInstance();
   speechEngine.parameterize(cvox.MathmlStore.getInstance());
   traverse.initialize(node);
   var ret = speechEngine.evaluateNode(traverse.activeNode);
   if (ret == []) {
     return [new cvox.NavDescription({'text': 'empty math'})];
   }
   if (cvox.ChromeVox.verbosity == cvox.VERBOSITY_VERBOSE) {
     ret[ret.length - 1].annotation = 'math';
   }
   ret[0].pushEarcon(cvox.Earcon.MATH);
   return ret;
 };