Generalize DeclarationBuilder.resolveTypes.

pkg/front_end/lib/src/fasta/source/outline_builder.dart

Index: pkg/front_end/lib/src/fasta/source/outline_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/source/outline_builder.dart b/pkg/front_end/lib/src/fasta/source/outline_builder.dart
index 580ddc7e7b0e8faf1d5cbecf0cbd15a06887c59f..b9a8476986aead2d6f5c362720fab9149201face 100644
--- a/pkg/front_end/lib/src/fasta/source/outline_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/outline_builder.dart
@@ -500,6 +500,11 @@ class OutlineBuilder extends UnhandledListener {
   }
 
   @override
+  void beginFactoryMethod(Token token) {
+    library.beginNestedDeclaration(null, hasMembers: false);
+  }
+
+  @override
   void endFactoryMethod(Token beginToken, Token endToken) {
     debugEvent("FactoryMethod");
     MethodBody kind = pop();