Remove deprecated string features.

sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index 7e220b02d8217be9509372d835e526446d162d51..044ee4c795449495399db56032551b8e29ae3075 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -29689,7 +29689,7 @@ class KeyboardEventController {
   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;
@@ -29824,8 +29824,8 @@ class KeyboardEventController {
       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;
       }