Revert "Change some platform libraries to use `part of URI`."

sdk/lib/convert/byte_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 dart.convert;
 
 /**
  * The [ByteConversionSink] provides an interface for converters to
  * efficiently transmit byte data.
  *
  * Instead of limiting the interface to one non-chunked list of bytes it
  * accepts its input in chunks (themselves being lists of bytes).
  *
  * This abstract class will likely get more methods over time. Implementers are
  * urged to extend or mix in [ByteConversionSinkBase] to ensure that their
@@ skipping 94 matching lines @@
     v |= v >> 8;
     v |= v >> 16;
     v++;
     return v;
   }
 
   void close() {
     _callback(_buffer.sublist(0, _bufferIndex));
   }
 }