WebCrypto: Add parsing for the algorithm parameter AesDerivedKey.

public/platform/WebCryptoAlgorithmParams.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 304 matching lines @@
     }
 
     virtual WebCryptoAlgorithmParamsType type() const { return WebCryptoAlgorithmParamsTypeEcdhKeyDeriveParams; }
 
     const WebCryptoKey publicKey() const { return m_publicKey; }
 
 private:
     const WebCryptoKey m_publicKey;
 };
 
+class WebCryptoAesDerivedKeyParams : public WebCryptoAlgorithmParams {
+public:
+    explicit WebCryptoAesDerivedKeyParams(unsigned short lengthBits)
+        : m_lengthBits(lengthBits)
+    {
+    }
+
+    virtual WebCryptoAlgorithmParamsType type() const override { return WebCryptoAlgorithmParamsTypeAesDerivedKeyParams; }
+
+    unsigned short lengthBits() const { return m_lengthBits; }
+
+private:
+    const unsigned short m_lengthBits;
+};
+
 } // namespace blink
 
 #endif