Move bit_cast from base/macros.h to its own header

courgette/difference_estimator.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // We want to measure the similarity of two sequences of bytes as a surrogate
 // for measuring how well a second sequence will compress differentially to the
 // first sequence.
 
 #include "courgette/difference_estimator.h"
 
 #include <stddef.h>
 #include <stdint.h>
+#include <string.h>
 
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
 
 namespace courgette {
 
 // Our difference measure is the number of k-tuples that occur in Subject that
 // don't occur in Base.
 const int kTupleSize = 4;
 
@@ skipping 95 matching lines @@
 
   if (mismatches == 0) {
     if (RegionsEqual(base->region(), subject->region()))
       return 0;
   }
   ++mismatches;  // Guarantee not zero.
   return mismatches;
 }
 
 }  // namespace