Fully polyfill KeyEvent so that you can programmatically create your own "keyboard" events.

tools/dom/src/KeyName.dart

Index: tools/dom/src/KeyName.dart
diff --git a/tools/dom/src/KeyName.dart b/tools/dom/src/KeyName.dart
index 402cdc25262bb12dbddf197f77c881f4e7a3c2bf..907614743a71c1cff40ecbfa5b90f6302f7bb562 100644
--- a/tools/dom/src/KeyName.dart
+++ b/tools/dom/src/KeyName.dart
@@ -6,10 +6,10 @@ part of html;
 
 /**
  * Defines the standard keyboard identifier names for keys that are returned
- * by KeyEvent.getKeyboardIdentifier when the key does not have a direct
+ * by KeyboardEvent.getKeyboardIdentifier when the key does not have a direct
  * unicode mapping.
  */
-abstract class KeyName {
+abstract class _KeyName {
 
   /** The Accept (Commit, OK) key */
   static const String ACCEPT = "Accept";