Fixes for forgotten review comments.

pkg/analyzer_experimental/bin/coverage.dart

 // Copyright (c) 2013, 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 runtime.coverage;
 
 import 'dart:io';
 
-import 'package:args/args.dart' show ArgParser, ArgResults;
+import 'package:args/args.dart';
 
 import 'package:analyzer_experimental/src/services/runtime/log.dart' as log;
 import 'package:analyzer_experimental/src/services/runtime/coverage/coverage_impl.dart';
 
 
 main() {
   ArgResults options;
   try {
     options = _argParser.parse(new Options().arguments);
   } on FormatException catch (e) {
@@ skipping 51 matching lines @@
         allowed: ['method', 'block', 'statement'],
         defaultsTo: 'statement')
     ..addOption('out', help: 'The output file with statistics.')
     ..addOption(
         'port',
         help: 'The port to run server on, if 0 select any.',
         defaultsTo: '0');
 
 
 printUsage([var description = 'Code coverage tool for Dart.']) {
-  var buffer = new StringBuffer();
   var usage = _argParser.getUsage();
-  buffer.write(
-      '$description\n\n'
-      'Usage: coverage [options] <script>\n\n'
-      '$usage\n\n');
-  print(buffer.toString());
+  print('$description\n');
+  print('Usage: coverage [options] <script>\n');
+  print('$usage\n');
 }
 
 
 /// General error code.
 const ERROR = 1;