Fix keyboard commands on bookmarks page.

chrome/browser/resources/md_downloads/crisper.js

 // Copyright (c) 2013 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 Assertion support.
  */
 
 /**
  * Verify |condition| is truthy and return |condition| if so.
@@ skipping 1681 matching lines @@
 
       this._notifyingDescendant = true;
       descendant.notifyResize();
       this._notifyingDescendant = false;
     }
   };
 (function() {
     'use strict';
 
     /**
-     * Chrome uses an older version of DOM Level 3 Keyboard Events

[Dan Beam, 2016/07/12 19:59:30]

this is just gonna get replaced the next time we vulcanize the downloads page. 
this is from polymer somewhere.  it'd be hard to remove it.

-     *
-     * Most keys are labeled as text, but some are Unicode codepoints.
-     * Values taken from: http://www.w3.org/TR/2007/WD-DOM-Level-3-Events-20071221/keyset.html#KeySet-Set
-     */
-    var KEY_IDENTIFIER = {
-      'U+0008': 'backspace',
-      'U+0009': 'tab',
-      'U+001B': 'esc',
-      'U+0020': 'space',
-      'U+007F': 'del'
-    };
-
-    /**
      * Special table for KeyboardEvent.keyCode.
      * KeyBoardEvent.key is even better than that.
      *
      * Values from: https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent.keyCode#Value_of_keyCode
      */
     var KEY_CODE = {
       8: 'backspace',
       9: 'tab',
       13: 'enter',
       27: 'esc',
@@ skipping 9792 matching lines @@
     Manager.get().updateItem_(index, data);
   };
 
   return {Manager: Manager};
 });
 // 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.
 
 window.addEventListener('load', downloads.Manager.onLoad);