Add constructors to all the event classes.

client/html/src/OverflowEvent.dart

Index: client/html/src/OverflowEvent.dart
diff --git a/client/html/generated/src/interface/OverflowEvent.dart b/client/html/src/OverflowEvent.dart
similarity index 70%
rename from client/html/generated/src/interface/OverflowEvent.dart
rename to client/html/src/OverflowEvent.dart
index 2fc48fb9c59efb8c9bdabce2fe9fdc6134734c14..f76c72b022135ae0d11f8d26a6da6c0a69544786 100644
--- a/client/html/generated/src/interface/OverflowEvent.dart
+++ b/client/html/src/OverflowEvent.dart
@@ -2,9 +2,9 @@
 // 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 OverflowEvent extends Event factory OverflowEventWrappingImplementation {
 
-interface OverflowEvent extends Event {
+  OverflowEvent(int orient, bool horizontalOverflow, bool verticalOverflow);
 
   static final int BOTH = 2;
 
@@ -17,6 +17,4 @@ interface OverflowEvent extends Event {
   int get orient();
 
   bool get verticalOverflow();
-
-  void initOverflowEvent(int orient, bool horizontalOverflow, bool verticalOverflow);
 }