Removing warnings from tests

runtime/observatory/tests/service/eval_internal_class_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.
 
-import 'dart:async';
-import 'dart:developer';
 import 'package:observatory/service_io.dart';
 import 'package:unittest/unittest.dart';
-import 'service_test_common.dart';
 import 'test_helper.dart';
 
 var tests = [
 
 (Isolate isolate) async {
   Library root = await isolate.rootLibrary.load();
 
   Class classLibrary = await root.clazz.load();
   print(classLibrary);
   var result = await classLibrary.evaluate('3 + 4');
@@ skipping 15 matching lines @@
   print(classArray);
   result = await classArray.evaluate('3 + 4');
   print(result);
   expect(result is Instance, isTrue);
   expect(result.valueAsString, equals('7'));
 },
 
 ];
 
 main(args) => runIsolateTests(args, tests);