Use package: URIs for files in lib

pkg/analyzer/test/source/package_map_resolver_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.source.package_map_resolver;
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/source/package_map_resolver.dart';
 import 'package:analyzer/src/generated/source.dart';
@@ skipping 144 matching lines @@
     provider.newFile(pkgFileB, 'library lib_b;');
     PackageMapUriResolver resolver =
         new PackageMapUriResolver(provider, <String, List<Folder>>{
       'pkgA': [provider.getResource('/pkgA/lib/')],
       'pkgB': [provider.getResource('/pkgB/lib/')]
     });
     {
       Source source = _createFileSource('/pkgA/lib/libA.dart');
       Uri uri = resolver.restoreAbsolute(source);
       expect(uri, isNotNull);
-      expect(uri.path, 'package:pkgA/libA.dart');
+      expect(uri.toString(), 'package:pkgA/libA.dart');
     }
     {
       Source source = _createFileSource('/pkgB/lib/src/libB.dart');
       Uri uri = resolver.restoreAbsolute(source);
       expect(uri, isNotNull);
-      expect(uri.path, 'package:pkgB/src/libB.dart');
+      expect(uri.toString(), 'package:pkgB/src/libB.dart');
     }
     {
       Source source = _createFileSource('/no/such/file');
       Uri uri = resolver.restoreAbsolute(source);
       expect(uri, isNull);
     }
   }
 
   Source _createFileSource(String path) {
     return new NonExistingSource(path, UriKind.FILE_URI);
   }
 }