Use relative URIs for core library part-of statements.

sdk/lib/vmservice/asset.dart

 // Copyright (c) 2015, 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.
 
-part of dart._vmservice;
+part of "vmservice.dart";
 
 class Asset {
   final String name;
   final Uint8List data;
 
   Asset(this.name, this.data);
 
   String get mimeType {
     var extensionStart = name.lastIndexOf('.');
     var extension = name.substring(extensionStart + 1);
@@ skipping 185 matching lines @@
     int type = _readType(_bs);
     _bs.seekToNextBlock(tarHeaderSize);
     if (type != tarHeaderFileType) {
       _skipContents(_bs, size);
       return null;
     }
     Uint8List bytes = _readContents(_bs, size);
     return new Asset(filename, bytes);
   }
 }