Add constructors to all the event classes.

client/html/src/AnimationEvent.dart

Index: client/html/src/AnimationEvent.dart
diff --git a/client/html/generated/src/interface/AnimationEvent.dart b/client/html/src/AnimationEvent.dart
similarity index 56%
rename from client/html/generated/src/interface/AnimationEvent.dart
rename to client/html/src/AnimationEvent.dart
index 309a92ea849afd0a925ce2b2cd3e401aec0ca83e..0a9eb62f3b56b50e017b10b42ddcbc6855cbee93 100644
--- a/client/html/generated/src/interface/AnimationEvent.dart
+++ b/client/html/src/AnimationEvent.dart
@@ -2,13 +2,12 @@
 // 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 AnimationEvent extends Event factory AnimationEventWrappingImplementation {
 
-interface AnimationEvent extends Event {
+  AnimationEvent(String type, String propertyName, double elapsedTime,
+      [bool canBubble, bool cancelable]);
 
   String get animationName();
 
   num get elapsedTime();
-
-  void initWebKitAnimationEvent(String typeArg, bool canBubbleArg, bool cancelableArg, String animationNameArg, num elapsedTimeArg);
 }