Remove CryptAcquireContextLocked.

crypto/capi_util.h

 // Copyright (c) 2012 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.
 
 #ifndef CRYPTO_CAPI_UTIL_H_
 #define CRYPTO_CAPI_UTIL_H_
 
 #include <windows.h>
 #include <stddef.h>
 
 #include "crypto/crypto_export.h"
-#include "crypto/wincrypt_shim.h"
 
 namespace crypto {
 
-// CryptAcquireContext when passed CRYPT_NEWKEYSET or CRYPT_DELETEKEYSET in
-// flags is not thread-safe. For such calls, we create a global lock to
-// synchronize it.
-//
-// From "Threading Issues with Cryptographic Service Providers",
-// <http://msdn.microsoft.com/en-us/library/aa388149(v=VS.85).aspx>:
-//
-// "The CryptAcquireContext function is generally thread safe unless
-// CRYPT_NEWKEYSET or CRYPT_DELETEKEYSET is specified in the dwFlags
-// parameter."
-CRYPTO_EXPORT BOOL CryptAcquireContextLocked(HCRYPTPROV* prov,
-                                             LPCWSTR container,
-                                             LPCWSTR provider,
-                                             DWORD prov_type,
-                                             DWORD flags);
-
 // Wrappers of malloc and free for CryptoAPI routines that need memory
 // allocators, such as in CRYPT_DECODE_PARA. Such routines require WINAPI
 // calling conventions.
 CRYPTO_EXPORT void* WINAPI CryptAlloc(size_t size);
 CRYPTO_EXPORT void WINAPI CryptFree(void* p);
 
 }  // namespace crypto
 
 #endif  // CRYPTO_CAPI_UTIL_H_