Return const by ref instead of value

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 298 matching lines @@
 
 class WebCryptoEcdhKeyDeriveParams : public WebCryptoAlgorithmParams {
 public:
     explicit WebCryptoEcdhKeyDeriveParams(const WebCryptoKey& publicKey)
         : m_publicKey(publicKey)
     {
     }
 
     virtual WebCryptoAlgorithmParamsType type() const { return WebCryptoAlgorithmParamsTypeEcdhKeyDeriveParams; }
 
-    const WebCryptoKey publicKey() const { return m_publicKey; }
+    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)
     {
@@ skipping 45 matching lines @@
     unsigned iterations() const { return m_iterations; }
 
 private:
     const WebVector<unsigned char> m_salt;
     const unsigned m_iterations;
 };
 
 } // namespace blink
 
 #endif