WebCrypto: Add WebKit API structure for keys.

public/platform/WebCryptoAlgorithm.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 73 matching lines @@
         return *this;
     }
 
     WEBKIT_EXPORT WebCryptoAlgorithmId algorithmId() const;
     WEBKIT_EXPORT const char* algorithmName() const;
 
     WEBKIT_EXPORT WebCryptoAlgorithmParamsType paramsType() const;
 
     // Retrieves the type-specific parameters. The algorithm contains at most 1
     // type of parameters. Retrieving an invalid parameter will return 0.
-    WebCryptoAesCbcParams* aesCbcParams() const;
-    WebCryptoAesKeyGenParams* aesKeyGenParams() const;
+    WEBKIT_EXPORT WebCryptoAesCbcParams* aesCbcParams() const;
+    WEBKIT_EXPORT WebCryptoAesKeyGenParams* aesKeyGenParams() const;
 
 private:
     WEBKIT_EXPORT void assign(const WebCryptoAlgorithm& other);
     WEBKIT_EXPORT void reset();
 
     WebPrivatePtr<WebCryptoAlgorithmPrivate> m_private;
 };
 
 } // namespace WebKit
 
 #endif