Revert "Switch libraries to using new tags."

sdk/lib/crypto/hash_utils.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.
 
-part of dart.crypto;
-
 // Constants.
 const _MASK_8 = 0xff;
 const _MASK_32 = 0xffffffff;
 const _BITS_PER_BYTE = 8;
 const _BYTES_PER_WORD = 4;
 
 // Helper functions used by more than one hasher.
 
 // Rotate left limiting to unsigned 32-bit values.
 int _rotl32(int val, int shift) {
@@ skipping 130 matching lines @@
   // Hasher state.
   final int _chunkSizeInWords;
   final int _digestSizeInWords;
   final bool _bigEndianWords;
   int _lengthInBytes = 0;
   List<int> _pendingData;
   List<int> _currentChunk;
   List<int> _h;
   bool _digestCalled = false;
 }