Stop propagating return types for top-level function declarations

pkg/analyzer/test/generated/incremental_resolver_test.dart

Index: pkg/analyzer/test/generated/incremental_resolver_test.dart
diff --git a/pkg/analyzer/test/generated/incremental_resolver_test.dart b/pkg/analyzer/test/generated/incremental_resolver_test.dart
index a08ede73fdfbb34980e10984346cb78f5b00521e..ccb5af4ce0e7d091999c58d4bbc1a75d671c965c 100644
--- a/pkg/analyzer/test/generated/incremental_resolver_test.dart
+++ b/pkg/analyzer/test/generated/incremental_resolver_test.dart
@@ -2346,6 +2346,41 @@ class A {
 ''');
   }
 
+  void test_true_functionExpression() {
+    _assertMatches(r'''
+import 'dart:async';
+
+class A {
+  Future<int> mmm() async {
+    return 42;
+  }
+
+  a() {
+    mmm().then((p1) {
+      return p1.toString();
+    }).then((p2) {
+      print(p2);
+    });
+  }
+}
+''', r'''import 'dart:async';
+
+class A {
+  Future<int> mmm() async {
+    return 42;
+  }
+
+  a() {
+    mmm().then((int p1) {
+      return p1.toString();
+    }).then((String p2) {
+      print(p2);
+    });
+  }
+}
+''');
+  }
+
   void test_true_functionTypeAlias_list_reorder() {
     _assertMatches(
         r'''