Fix tests and analysis warnings and release 0.12.0-beta.9.

test/runner/browser/firefox_test.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.
 
 @TestOn("vm")
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:test/test.dart';
 import 'package:test/src/runner/browser/firefox.dart';
 import 'package:test/src/util/io.dart';
 import 'package:shelf/shelf.dart' as shelf;
 import 'package:shelf/shelf_io.dart' as shelf_io;
 import 'package:shelf_web_socket/shelf_web_socket.dart';
 
+import '../../utils.dart';
+
 void main() {
   group("running JavaScript", () {
     // The JavaScript to serve in the server. We use actual JavaScript here to
     // avoid the pain of compiling to JS in a test
     var javaScript;
 
     var servePage = (request) {
       var path = request.url.path;
 
       // We support both shelf 0.5.x and 0.6.x. The former has a leading "/"
@@ skipping 101 matching lines @@
     return shelf_io.serve(expectAsync((_) {}, count: 0), 'localhost', 0)
         .then((server) {
       var firefox = new Firefox(baseUrlForAddress(server.address, server.port));
       return firefox.close().whenComplete(server.close);
     });
   });
 
   test("reports an error in onExit", () {
     var firefox = new Firefox("http://dart-lang.org",
         executable: "_does_not_exist");
-    expect(firefox.onExit, throwsA(new isInstanceOf<ProcessException>()));
+    expect(firefox.onExit, throwsA(isApplicationException(startsWith(
+        "Failed to start Firefox: No such file or directory"))));
   });
 }