Handle field initializers correctly.

pkg/dart_parser/lib/src/listener.dart

Index: pkg/dart_parser/lib/src/listener.dart
diff --git a/pkg/dart_parser/lib/src/listener.dart b/pkg/dart_parser/lib/src/listener.dart
index 63d0188d6f021a7f083afb978300b04a372429f8..bf9e25b1ea5fdc861d82fdeceb8757bc19bc89d2 100644
--- a/pkg/dart_parser/lib/src/listener.dart
+++ b/pkg/dart_parser/lib/src/listener.dart
@@ -316,6 +316,10 @@ class Listener {
     logEvent("FieldInitializer");
   }
 
+  void handleNoFieldInitializer(Token token) {
+    logEvent("NoFieldInitializer");
+  }
+
   void beginVariableInitializer(Token token) {}
 
   void endVariableInitializer(Token assignmentOperator) {