Allow multiple dirs per package in the data returned by "pub list".

pkg/analysis_server/test/domain_analysis_test.dart

 // Copyright (c) 2014, 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.domain.analysis;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/constants.dart';
@@ skipping 560 matching lines @@
   }
 
   test_setRoots_packages() {
     // prepare package
     String pkgFile = '/packages/pkgA/libA.dart';
     resourceProvider.newFile(pkgFile, '''
 library lib_a;
 class A {}
 ''');
     packageMapProvider.packageMap['pkgA'] =
-        resourceProvider.getResource('/packages/pkgA');
+        [resourceProvider.getResource('/packages/pkgA')];
     addTestFile('''
 import 'package:pkgA/libA.dart';
 main(A a) {
 }
 ''');
     // create project and wait for analysis
     createProject();
     return waitForTasksFinished().then((_) {
       // if 'package:pkgA/libA.dart' was resolved, then there are no errors
       expect(filesErrors[testFile], isEmpty);
       // packages file also was resolved
       expect(filesErrors[pkgFile], isEmpty);
     });
   }
 }