[webcrypto] Implement PBKDF2 (blink-side)

public/platform/WebCryptoKeyAlgorithmParams.h

 /*
  * Copyright (C) 2014 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 188 matching lines @@
         case WebCryptoNamedCurveP521:
             dict->setString("namedCurve", "P-521");
             break;
         }
     }
 
 private:
     const WebCryptoNamedCurve m_namedCurve;
 };
 
+class WebCryptoPbkdf2KeyAlgorithmParams : public WebCryptoKeyAlgorithmParams {
+public:
+    explicit WebCryptoPbkdf2KeyAlgorithmParams() { }
+    virtual void writeToDictionary(WebCryptoKeyAlgorithmDictionary* dict) const
+    {
+    }
+};
 } // namespace blink
 
 #endif