Fix a bunch of pub tests that started running "pub get".

test/serve/web_socket/url_to_asset_id_with_line_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS d.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 pub_tests;
 
 import '../../descriptor.dart' as d;
 import '../../test_pub.dart';
 import '../utils.dart';
 
 main() {
   integration("provides output line number if given source one", () {
     d.dir(appPath, [
       d.appPubspec(),
       d.dir("web", [
         d.file("main.dart", "main")
       ])
     ]).create();
 
-    pubServe();
+    pubServe(shouldGetFirst: true);
 
     // Paths in web/.
     expectWebSocketResult("urlToAssetId", {
       "url": getServerUrl("web", "main.dart"),
       "line": 12345
     }, {
       "package": "myapp",
       "path": "web/main.dart",
       "line": 12345
     });
 
     endPubServe();
   });
 }