Reland: Simplify PRTimeToBaseTime implementation, add BaseTimeToPRTime.

crypto/nss_util.h

 // 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.
 
 #ifndef CRYPTO_NSS_UTIL_H_
 #define CRYPTO_NSS_UTIL_H_
 #pragma once
 
 #include <string>
 #include "base/basictypes.h"
@@ skipping 131 matching lines @@
 // provided to ensure that sensitive data wouldn't be exposed in plain text in
 // case when an attacker would somehow gain access to all content within
 // cryptohome.
 CRYPTO_EXPORT SymmetricKey* GetSupplementalUserKey();
 #endif
 
 // Convert a NSS PRTime value into a base::Time object.
 // We use a int64 instead of PRTime here to avoid depending on NSPR headers.
 CRYPTO_EXPORT base::Time PRTimeToBaseTime(int64 prtime);
 
+// Convert a base::Time object into a PRTime value.
+// We use a int64 instead of PRTime here to avoid depending on NSPR headers.
+CRYPTO_EXPORT int64 BaseTimeToPRTime(base::Time time);
+
 #if defined(USE_NSS)
 // Exposed for unittests only.  |path| should be an existing directory under
 // which the DB files will be placed.  |description| is a user-visible name for
 // the DB, as a utf8 string, which will be truncated at 32 bytes.
 CRYPTO_EXPORT bool OpenTestNSSDB(const FilePath& path, const char* description);
 CRYPTO_EXPORT void CloseTestNSSDB();
 
 // NSS has a bug which can cause a deadlock or stall in some cases when writing
 // to the certDB and keyDB. It also has a bug which causes concurrent key pair
 // generations to scribble over each other. To work around this, we synchronize
@@ skipping 13 matching lines @@
  private:
   base::Lock *lock_;
   DISALLOW_COPY_AND_ASSIGN(AutoNSSWriteLock);
 };
 
 #endif  // defined(USE_NSS)
 
 }  // namespace crypto
 
 #endif  // CRYPTO_NSS_UTIL_H_