Use package: URIs for files in lib

pkg/analyzer/lib/source/package_map_resolver.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 source.package_map_resolver;
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/util/asserts.dart' as asserts;
 
@@ skipping 65 matching lines @@
 
   @override
   Uri restoreAbsolute(Source source) {
     String sourcePath = source.fullName;
     for (String pkgName in packageMap.keys) {
       List<Folder> pkgFolders = packageMap[pkgName];
       for (Folder pkgFolder in pkgFolders) {
         String pkgFolderPath = pkgFolder.path;
         if (sourcePath.startsWith(pkgFolderPath)) {
           String relPath = sourcePath.substring(pkgFolderPath.length);
-          return new Uri(path: '$PACKAGE_SCHEME:$pkgName$relPath');
+          return Uri.parse('$PACKAGE_SCHEME:$pkgName$relPath');
         }
       }
     }
     return null;
   }
 
   /**
    * Returns `true` if [uri] is a `package` URI.
    */
   static bool isPackageUri(Uri uri) {
     return uri.scheme == PACKAGE_SCHEME;
   }
 }