Typecheck some of ui/webui/resources/js/ with Closure compiler.

chrome/browser/resources/ntp4/tile_page.js

 // Copyright (c) 2012 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.
 
 cr.define('ntp', function() {
   'use strict';
 
   // We can't pass the currently dragging tile via dataTransfer because of
   // http://crbug.com/31037
   var currentlyDraggingTile = null;
@@ skipping 1354 matching lines @@
       return false;
     },
 
     /**
      * Called to accept a drag drop. Will not be called for in-page drops.
      * @param {Object} dataTransfer The data transfer object that holds the drop
      *     data. This should only be used if currentlyDraggingTile is null.
      * @param {number} index The tile index at which the drop occurred.
      */
     addDragData: function(dataTransfer, index) {
-      assert(false);
+      assertNotReached();
     },
 
     /**
      * Called when a tile has been moved (via dragging). Override this to make
      * backend updates.
      * @param {Node} draggedTile The tile that was dropped.
      * @param {number} prevIndex The previous index of the tile.
      */
     tileMoved: function(draggedTile, prevIndex) {
     },
 
     /**
      * Sets the drop effect on |dataTransfer| to the desired value (e.g.
      * 'copy').
      * @param {Object} dataTransfer The drag event dataTransfer object.
      */
     setDropEffect: function(dataTransfer) {
-      assert(false);
+      assertNotReached();
     },
   };
 
   return {
     getCurrentlyDraggingTile: getCurrentlyDraggingTile,
     setCurrentDropEffect: setCurrentDropEffect,
     TilePage: TilePage,
   };
 });