Fix dartanalyzer issue with const

sdk/lib/html/src/KeyboardEventController.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of html;
 
 /**
  * Works with KeyboardEvent and KeyEvent to determine how to expose information
  * about Key(board)Events. This class functions like an EventListenerList, and
  * provides a consistent interface for the Dart
@@ skipping 17 matching lines @@
   /** The set of functions that wish to be notified when a KeyEvent happens. */
   List<Function> _callbacks;
 
   /** The type of KeyEvent we are tracking (keyup, keydown, keypress). */
   String _type;
 
   /** The element we are watching for events to happen on. */
   EventTarget _target;
 
   // The distance to shift from upper case alphabet Roman letters to lower case.
-  const int _ROMAN_ALPHABET_OFFSET = "a".charCodes[0] - "A".charCodes[0];
+  int _ROMAN_ALPHABET_OFFSET = "a".charCodes[0] - "A".charCodes[0];

[blois, 2012/11/30 01:24:47]

final

 
   // Instance members referring to the internal event handlers because closures
   // are not hashable.
   var _keyUp, _keyDown, _keyPress;
 
   /**
    * An enumeration of key identifiers currently part of the W3C draft for DOM3
    * and their mappings to keyCodes.
    * http://www.w3.org/TR/DOM-Level-3-Events/keyset.html#KeySet-Set
    */
@@ skipping 347 matching lines @@
       _keyDownList = _keyDownList.filter((element) => element != toRemove);
     } else if (_keyDownList.length > 0) {
       // This happens when we've reached some international keyboard case we
       // haven't accounted for or we haven't correctly eliminated all browser
       // inconsistencies. Filing bugs on when this is reached is welcome! 
       _keyDownList.removeLast(); 
     }
     _dispatch(e);
   }
 }