Add constructors to all the event classes.

client/html/src/XMLHttpRequestProgressEvent.dart

Index: client/html/src/XMLHttpRequestProgressEvent.dart
diff --git a/client/html/generated/src/interface/XMLHttpRequestProgressEvent.dart b/client/html/src/XMLHttpRequestProgressEvent.dart
similarity index 51%
rename from client/html/generated/src/interface/XMLHttpRequestProgressEvent.dart
rename to client/html/src/XMLHttpRequestProgressEvent.dart
index c0e9b12ad7f2a479e89aeffd8d8425bfed9dd9a0..611ae884f2689fdcb83a4138e836919acfae2081 100644
--- a/client/html/generated/src/interface/XMLHttpRequestProgressEvent.dart
+++ b/client/html/src/XMLHttpRequestProgressEvent.dart
@@ -2,9 +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 XMLHttpRequestProgressEvent extends ProgressEvent factory XMLHttpRequestProgressEventWrappingImplementation {
 
-interface XMLHttpRequestProgressEvent extends ProgressEvent {
+  XMLHttpRequestProgressEvent(String type, int loaded, [bool canBubble,
+      bool cancelable, bool lengthComputable, int total]);
 
   int get position();