Don't implicitly run "pub get".

test/dart2js/source_maps_include_core_libs_test.dart

 // Copyright (c) 2013, 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.
 
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 
 main() {
   // This test is a bit shaky. Since dart2js is free to inline things, it's
   // not precise as to which source libraries will actually be referenced in
   // the source map. But this tries to use a type in the core library
   // (Duration) and validate that its source ends up in the source map.
   integration("Dart core libraries are available to source maps", () {
     d.dir(appPath, [
       d.appPubspec(),
       d.dir("web", [
         d.file("main.dart", "main() => new Duration().toString();"),
         d.dir("sub", [
           d.file("main.dart", "main() => new Duration().toString();")
         ])
       ])
     ]).create();
 
+    pubGet();
     schedulePub(args: ["build", "--mode", "debug"],
         output: new RegExp(r'Built \d+ files to "build".'),
         exitCode: 0);
 
     d.dir(appPath, [
       d.dir("build", [
         d.dir("web", [
           d.matcherFile("main.dart.js.map",
               contains(r"packages/$sdk/lib/core/duration.dart")),
           d.dir("sub", [
             d.matcherFile("main.dart.js.map",
                 contains(r"../packages/$sdk/lib/core/duration.dart"))
           ]),
           d.dir("packages", [
             d.dir(r"$sdk", [
               d.dir("lib", [
                 d.dir(r"core", [
                   d.matcherFile("duration.dart",
                       contains("class Duration"))
                 ])
               ])
             ])
           ])
         ])
       ])
     ]).validate();
   });
 }