crypto: Add critpto_api.h and annotate the current exports needed to run

crypto/symmetric_key.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_SYMMETRIC_KEY_H_
 #define CRYPTO_SYMMETRIC_KEY_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
+#include "crypto/crypto_api.h"
 
 #if defined(USE_NSS)
 #include "crypto/scoped_nss_types.h"
 #elif defined(OS_MACOSX)
 #include <Security/cssmtype.h>
 #elif defined(OS_WIN)
 #include "crypto/scoped_capi_types.h"
 #endif
 
 namespace crypto {
 
 // Wraps a platform-specific symmetric key and allows it to be held in a
 // scoped_ptr.
-class SymmetricKey {
+class CRYPTO_API SymmetricKey {
  public:
   // Defines the algorithm that a key will be used with. See also
   // classs Encrptor.
   enum Algorithm {
     AES,
     HMAC_SHA1,
   };
 
   virtual ~SymmetricKey();
 
@@ skipping 59 matching lines @@
   // fails with NTE_BAD_KEY/NTE_BAD_LEN
   std::string raw_key_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(SymmetricKey);
 };
 
 }  // namespace crypto
 
 #endif  // CRYPTO_SYMMETRIC_KEY_H_