Use relative URIs for core library part-of statements.

sdk/lib/convert/chunked_conversion.dart

 // Copyright (c) 2013, 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.convert;
+part of "convert.dart";
 
 typedef void _ChunkedConversionCallback<T>(T accumulated);
 
 /**
  * A [ChunkedConversionSink] is used to transmit data more efficiently between
  * two converters during chunked conversions.
  *
  * The basic `ChunkedConversionSink` is just a [Sink], and converters should
  * work with a plain `Sink`, but may work more efficiently with certain
  * specialized types of `ChunkedConversionSink`.
@@ skipping 71 matching lines @@
   }
 
   void addError(Object error, [StackTrace stackTrace]) {
     _eventSink.addError(error, stackTrace);
   }
 
   void close() {
     _chunkedSink.close();
   }
 }