Add crypto/wincrypt_shim.h wrapper header to resolve BoringSSL conflicts.

crypto/crypto.gypi

 # Copyright 2014 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.
 
 {
   'variables': {
     # Put all transitive dependencies for Windows HMAC here.
     # This is required so that we can build them for nacl win64.
     'variables': {
       'hmac_win64_related_sources': [
         'hmac.cc',
         'hmac.h',
         'hmac_win.cc',
         'secure_util.cc',
         'secure_util.h',
         'symmetric_key.h',
         'symmetric_key_win.cc',
         'third_party/nss/chromium-blapi.h',
         'third_party/nss/chromium-blapit.h',
         'third_party/nss/chromium-prtypes.h',
         'third_party/nss/chromium-sha256.h',
         'third_party/nss/sha512.cc',
+        'wincrypt.h',
       ],
     },
     'hmac_win64_related_sources': [ '<@(hmac_win64_related_sources)' ],
     'crypto_sources': [
       # NOTE: all transitive dependencies of HMAC on windows need
       #     to be placed in the source list above.
       '<@(hmac_win64_related_sources)',
       'apple_keychain.h',
       'apple_keychain_ios.mm',
       'apple_keychain_mac.mm',
@@ skipping 62 matching lines @@
       'signature_verifier_openssl.cc',
       'symmetric_key_nss.cc',
       'symmetric_key_openssl.cc',
       'third_party/nss/chromium-nss.h',
       'third_party/nss/pk11akey.cc',
       'third_party/nss/rsawrapr.c',
       'third_party/nss/secsign.cc',
     ]
   }
 }