Support Package Resolution Configuration files.

tests/compiler/dart2js/import_mirrors_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.
 
 // Test that the compiler emits a warning on import of 'dart:mirrors' unless
 // the flag --enable-experimental-mirrors is used.
 
 library dart2js.test.import;
 
 import 'dart:async';
@@ skipping 48 matching lines @@
       "main.dart => first.dart => second.dart => dart:mirrors",
 };
 
 const INDIRECT_PACKAGE_IMPORT1 = const {
   '/main.dart': '''
 import 'first.dart';
 
 main() {}
 ''',
   '/first.dart': '''
-import 'package:second.dart';
+import 'package:second/second.dart';
 ''',
-  '/pkg/second.dart': '''
+  '/pkg/second/second.dart': '''
 import 'dart:mirrors';
 ''',
 
   'paths':
-      "first.dart => package:second.dart => dart:mirrors",
+      "first.dart => package:second => dart:mirrors",
   'verbosePaths':
-      "main.dart => first.dart => package:second.dart => dart:mirrors",
+      "main.dart => first.dart => package:second/second.dart => dart:mirrors",
 };
 
 const INDIRECT_PACKAGE_IMPORT2 = const {
   '/main.dart': '''
 import 'first.dart';
 
 main() {}
 ''',
   '/first.dart': '''
 import 'package:package-name/second.dart';
@@ skipping 315 matching lines @@
       DUAL_INDIRECT_IMPORT3,
       DUAL_INDIRECT_PACKAGE_IMPORT1,
       DIRECT_EXPORT,
       INDIRECT_EXPORT1,
       INDIRECT_EXPORT2,
       INDIRECT_PACKAGE_EXPORT1,
       INDIRECT_PACKAGE_EXPORT2],
       (map) => checkPaths(map)
   ));
 }