Fix invocations of the MD5 constructors.

lib/src/hash_sink.dart

 // Copyright (c) 2012, 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 crypto.hash_base;
 
 import 'dart:typed_data';
 
 import 'package:typed_data/typed_data.dart';
 
 import 'digest.dart';
-import 'hash.dart';
 import 'utils.dart';
 
 /// A base class for [Sink] implementations for hash algorithms.
 ///
 /// Subclasses should override [updateHash] and [digest].
 abstract class HashSink implements Sink<List<int>> {
   /// The inner sink that this should forward to.
   final Sink<Digest> _sink;
 
   /// Whether the hash function operates on big-endian words.
@@ skipping 108 matching lines @@
     // hash.
     var offset = _pendingData.length;
     _pendingData.addAll(new Uint8List(8));
     _pendingData.buffer.asByteData().setUint64(offset, lengthInBits, _endian);
   }
 
   /// Rounds [val] up to the next multiple of [n], as long as [n] is a power of
   /// two.
   int _roundUp(int val, int n) => (val + n - 1) & -n;
 }