Add constructors to all the event classes.

client/html/src/PageTransitionEvent.dart

Index: client/html/src/PageTransitionEvent.dart
diff --git a/client/html/generated/src/interface/PageTransitionEvent.dart b/client/html/src/PageTransitionEvent.dart
similarity index 56%
rename from client/html/generated/src/interface/PageTransitionEvent.dart
rename to client/html/src/PageTransitionEvent.dart
index a3211ac8d553db47532f5844d1802d1ab614bcb0..c8a3ffa8d092598d61de23902800f31b4e690c18 100644
--- a/client/html/generated/src/interface/PageTransitionEvent.dart
+++ b/client/html/src/PageTransitionEvent.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 PageTransitionEvent extends Event factory PageTransitionEventWrappingImplementation {
 
-interface PageTransitionEvent extends Event {
+  PageTransitionEvent(String type, [bool canBubble, bool cancelable,
+      bool persisted]);
 
   bool get persisted();
-
-  void initPageTransitionEvent(String typeArg, bool canBubbleArg, bool cancelableArg, bool persisted);
 }