Remove CryptAcquireContextLocked.

crypto/capi_util.h

Index: crypto/capi_util.h
diff --git a/crypto/capi_util.h b/crypto/capi_util.h
index 69410334b0588093efba0cb3fdbd900d5c94f169..11e2b7bb6edaf2a83806bcf514ff6c835dea382a 100644
--- a/crypto/capi_util.h
+++ b/crypto/capi_util.h
@@ -9,26 +9,9 @@
 #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.