Add constructors to all the event classes.

client/html/src/CompositionEvent.dart

Index: client/html/src/CompositionEvent.dart
diff --git a/client/html/generated/src/interface/CompositionEvent.dart b/client/html/src/CompositionEvent.dart
similarity index 54%
rename from client/html/generated/src/interface/CompositionEvent.dart
rename to client/html/src/CompositionEvent.dart
index 9f3179995fcb339640b54007bcda19b5d5a79a2d..7aba5f16f0d4574a82293c49e625658c7463246a 100644
--- a/client/html/generated/src/interface/CompositionEvent.dart
+++ b/client/html/src/CompositionEvent.dart
@@ -2,11 +2,10 @@
 // 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.
 
-// WARNING: Do not edit - generated code.
+interface CompositionEvent extends UIEvent factory CompositionEventWrappingImplementation {
 
-interface CompositionEvent extends UIEvent {
+  CompositionEvent(String type, Window view, String data, [bool canBubble,
+      bool cancelable]);
 
   String get data();
-
-  void initCompositionEvent(String typeArg, bool canBubbleArg, bool cancelableArg, Window viewArg, String dataArg);
 }