suggest fields rather than synthetic getters

pkg/analysis_server/lib/src/protocol_server.dart

Index: pkg/analysis_server/lib/src/protocol_server.dart
diff --git a/pkg/analysis_server/lib/src/protocol_server.dart b/pkg/analysis_server/lib/src/protocol_server.dart
index 9f12f18a1ac72765b32351d9980f4499d306ab4f..d8835118aa4d36e4a99bfcc4574225f8b98aa3f1 100644
--- a/pkg/analysis_server/lib/src/protocol_server.dart
+++ b/pkg/analysis_server/lib/src/protocol_server.dart
@@ -370,6 +370,9 @@ String _getReturnTypeString(engine.Element element) {
     } else {
       return element.returnType.toString();
     }
+  } else if (element is engine.VariableElement) {
+    engine.DartType type = element.type;
+    return type != null ? type.displayName : 'dynamic';
   } else {
     return null;
   }