| Index: pkg/compiler/lib/src/serialization/serialization.dart | 
| diff --git a/pkg/compiler/lib/src/serialization/serialization.dart b/pkg/compiler/lib/src/serialization/serialization.dart | 
| index aee1504491a5d6550023deb624fabdbe5efad7cb..e127bbce2a878e5010d90c07b306e8c04e31f395 100644 | 
| --- a/pkg/compiler/lib/src/serialization/serialization.dart | 
| +++ b/pkg/compiler/lib/src/serialization/serialization.dart | 
| @@ -939,7 +939,7 @@ class DeserializerPlugin { | 
| void onElement(Element element, ObjectDecoder getDecoder(String tag)) {} | 
|  | 
| /// Called to deserialize custom data from [decoder]. | 
| -  dynamic onData(ObjectDecoder decoder) {} | 
| +  dynamic onData(ObjectDecoder decoder) => null; | 
| } | 
|  | 
| /// Context for parallel deserialization. | 
|  |