Remove deprecated string features.

tools/dom/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.
-  final int _ROMAN_ALPHABET_OFFSET = "a".charCodes[0] - "A".charCodes[0];
+  final int _ROMAN_ALPHABET_OFFSET = "a".codeUnits[0] - "A".codeUnits[0];
 
   StreamSubscription _keyUpSubscription, _keyDownSubscription,
       _keyPressSubscription;
 
   /**
    * 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
    */
   static Map<String, int> _keyIdentifier = {
@@ skipping 114 matching lines @@
    * reverse-engineering, we can also determine the keyCode.) Returns
    * KeyCode.UNKNOWN if the keycode could not be determined.
    */
   int _determineKeyCodeForKeypress(KeyboardEvent event) {
     // Note: This function is a work in progress. We'll expand this function
     // once we get more information about other keyboards.
     for (var prevEvent in _keyDownList) {
       if (prevEvent._shadowCharCode == event.charCode) {
         return prevEvent.keyCode;
       }
-      if ((event.shiftKey || _capsLockOn) && event.charCode >= "A".charCodes[0]
-          && event.charCode <= "Z".charCodes[0] && event.charCode +
+      if ((event.shiftKey || _capsLockOn) && event.charCode >= "A".codeUnits[0]
+          && event.charCode <= "Z".codeUnits[0] && event.charCode +
           _ROMAN_ALPHABET_OFFSET == prevEvent._shadowCharCode) {
         return prevEvent.keyCode;
       }
     }
     return KeyCode.UNKNOWN;
   }
 
   /**
    * Given the charater code returned from a keyDown [event], try to ascertain
    * and return the corresponding charCode for the character that was pressed.
@@ skipping 216 matching lines @@
           _keyDownList.where((element) => element != toRemove).toList();
     } 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);
   }
 }