Adapting observe to use smoke (this is built on top of the previous change that

pkg/smoke/lib/static.dart

Index: pkg/smoke/lib/static.dart
diff --git a/pkg/smoke/lib/static.dart b/pkg/smoke/lib/static.dart
index 95d22555dacdbda09925b0b5fc3ea5f09bdae30c..c2b518372ed046e0fa99c75ee8687f4106fbc825 100644
--- a/pkg/smoke/lib/static.dart
+++ b/pkg/smoke/lib/static.dart
@@ -164,6 +164,7 @@ class _GeneratedTypeInspectorService implements TypeInspectorService {
       throw new MissingCodeException('declarations for $type');
     }
     for (var decl in map.values) {
+      if (!options.includeFields && decl.isField) continue;
       if (!options.includeProperties && decl.isProperty) continue;
       if (options.excludeFinal && decl.isFinal) continue;
       if (!options.includeMethods && decl.isMethod) continue;