Don't disable downward inference inside initializers used for top-level inference.

pkg/analyzer/test/src/task/strong/inferred_type_test.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer.test.src.task.strong.inferred_type_test;
 
 import 'dart:async';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 810 matching lines @@
     f(/*info:INFERRED_TYPE_LITERAL*/[/*info:INFERRED_TYPE_LITERAL*/{y: x}]);
   }
   {
     int f(int x) => 0;
     A<int> a = /*info:INFERRED_TYPE_ALLOCATION*/new A(f);
   }
 }
 ''');
   }
 
+  test_downwardsInference_insideTopLevel() async {
+    await checkFileElement('''
+class A {
+  B<int> b;
+}
+
+class B<T> {
+  B(T x);
+}
+
+var t1 = new A()..b = /*info:INFERRED_TYPE_ALLOCATION*/new B(1);
+var t2 = <B<int>>[/*info:INFERRED_TYPE_ALLOCATION*/new B(2)];
+var t3 = /*info:INFERRED_TYPE_LITERAL*/[
+            /*info:INFERRED_TYPE_ALLOCATION*/new
+            /*error:TOP_LEVEL_TYPE_ARGUMENTS*/B(3)
+         ];
+''');
+  }
+
   test_downwardsInferenceAnnotations() async {
     await checkFileElement('''
 class Foo {
   const Foo(List<String> l);
   const Foo.named(List<String> l);
 }
 @Foo(/*info:INFERRED_TYPE_LITERAL*/const [])
 class Bar {}
 @Foo.named(/*info:INFERRED_TYPE_LITERAL*/const [])
 class Baz {}
@@ skipping 4151 matching lines @@
         .test_unsafeBlockClosureInference_functionCall_explicitTypeParam_viaExpr2();
   }
 
   @failingTest
   @override
   test_unsafeBlockClosureInference_functionCall_explicitTypeParam_viaExpr2_comment() async {
     await super
         .test_unsafeBlockClosureInference_functionCall_explicitTypeParam_viaExpr2_comment();
   }
 }