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

components/visitedlink/common/visitedlink_common.cc

 // Copyright (c) 2011 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.
 
 #include "components/visitedlink/common/visitedlink_common.h"
 
 #include <string.h>  // for memset()
 
+#include "base/bit_cast.h"
 #include "base/logging.h"
 #include "base/md5.h"
 #include "url/gurl.h"
 
 namespace visitedlink {
 
 const VisitedLinkCommon::Fingerprint VisitedLinkCommon::null_fingerprint_ = 0;
 const VisitedLinkCommon::Hash VisitedLinkCommon::null_hash_ = -1;
 
 VisitedLinkCommon::VisitedLinkCommon()
@@ skipping 74 matching lines @@
   // This is the same as "return *(Fingerprint*)&digest.a;" but if we do that
   // direct cast the alignment could be wrong, and we can't access a 64-bit int
   // on arbitrary alignment on some processors. This reinterpret_casts it
   // down to a char array of the same size as fingerprint, and then does the
   // bit cast, which amounts to a memcpy. This does not handle endian issues.
   return bit_cast<Fingerprint, uint8_t[8]>(
       *reinterpret_cast<uint8_t(*)[8]>(&digest.a));
 }
 
 }  // namespace visitedlink