pkg/test: Fix expected output in test/runner/runner_test.dart

lib/src/runner/browser/content_shell.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 test.runner.browser.content_shell;
 
 import 'dart:async';
 import 'dart:io';
 
-import 'package:path/path.dart' as p;
-
-import '../../util/io.dart';
 import 'browser.dart';
 
 /// A class for running an instance of the Dartium content shell.
 ///
 /// Most of the communication with the browser is expected to happen via HTTP,
 /// so this exposes a bare-bones API. The browser starts as soon as the class is
 /// constructed, and is killed when [close] is called.
 ///
 /// Any errors starting or running the process are reported through [onExit].
 class ContentShell implements Browser {
@@ skipping 35 matching lines @@
     _onProcessStarted.then((_) => _process.kill());
 
     // Swallow exceptions. The user should explicitly use [onExit] for these.
     return onExit.catchError((_) {});
   }
 
   /// Return the default executable for the current operating system.
   String _defaultExecutable() =>
       Platform.isWindows ? "content_shell.exe" : "content_shell";
 }