Handle parts as input in resolver.

tests/compiler/dart2js/dart2js_resolver_test.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 dart2js.dart2js_resolver.test;
+
+import 'dart:io';
+import 'package:async_helper/async_helper.dart';
+import 'package:compiler/src/dart2js_resolver.dart' as resolver;
+import 'analyze_test_test.dart';
+
+main() {
+  asyncTest(() async {
+    List<Uri> uriList = computeInputUris();
+    await resolver.resolve(uriList,
+        packageRoot: Uri.base.resolve(Platform.packageRoot),
+        platformConfig: "lib/dart_shared.platform");
+  });
+}