Revert "Tweak public APIs and use them in patch_sdk, dart2js, and kernel-service."

pkg/kernel/lib/target/vm.dart

 // Copyright (c) 2016, 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 kernel.target.vm;
 
 import '../ast.dart';
 import '../class_hierarchy.dart';
 import '../core_types.dart';
 import '../transformations/continuation.dart' as cont;
 import '../transformations/erasure.dart';
@@ skipping 251 matching lines @@
     // list first, and then populate it. That would create fewer objects. But as
     // this is currently only used in (statically resolved) no-such-method
     // handling, the current approach seems sufficient.
     return new MethodInvocation(
         new ListLiteral(elements)..fileOffset = offset,
         new Name("toList"),
         new Arguments(<Expression>[], named: <NamedExpression>[
           new NamedExpression("growable", new BoolLiteral(false))
         ]));
   }
-
-  // TODO(sigmund,ahe): limit this to `dart-ext` libraries only (see
-  // https://github.com/dart-lang/sdk/issues/29763).
-  @override
-  bool enableNative(Uri uri) => true;
-
-  @override
-  bool get nativeExtensionExpectsString => true;
 }