[webcrypto] Mark some methods in public API as const.

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 177 matching lines @@
         , m_hasAdditionalData(hasAdditionalData)
         , m_additionalData(additionalData, additionalDataSize)
         , m_hasTagLength(hasTagLength)
         , m_tagLength(tagLength)
     {
     }
 
     const WebVector<unsigned char>& iv() const { return m_iv; }
 
     bool hasAdditionalData() const { return m_hasAdditionalData; }
-    bool getAdditionalData(const WebVector<unsigned char>*& additionalData)
+    bool getAdditionalData(const WebVector<unsigned char>*& additionalData) const
     {
         if (!m_hasAdditionalData)
             return false;
         additionalData = &m_additionalData;
         return true;
     }
 
     bool hasTagLength() const { return m_hasTagLength; }
-    bool getTagLength(unsigned& tagLength)
+    bool getTagLength(unsigned& tagLength) const
     {
         if (!m_hasTagLength)
             return false;
         tagLength = m_tagLength;
         return true;
     }
 
 private:
     const WebVector<unsigned char> m_iv;
     const bool m_hasAdditionalData;
     const WebVector<unsigned char> m_additionalData;
     const bool m_hasTagLength;
     const unsigned char m_tagLength;
 };
 
 class WebCryptoRsaOaepParams : public WebCryptoAlgorithmParams {
 public:
     WebCryptoRsaOaepParams(const WebCryptoAlgorithm& hash, bool hasLabel, const unsigned char* label, unsigned labelSize)
         : WebCryptoAlgorithmParams(WebCryptoAlgorithmParamsTypeRsaOaepParams)
         , m_hash(hash)
         , m_hasLabel(hasLabel)
         , m_label(label, labelSize)
     {
         BLINK_ASSERT(!hash.isNull());
     }
 
     const WebCryptoAlgorithm& hash() const { return m_hash; }
 
     bool hasLabel() const { return m_hasLabel; }
-    bool getLabel(const WebVector<unsigned char>*& label)
+    bool getLabel(const WebVector<unsigned char>*& label) const
     {
         if (!m_hasLabel)
             return false;
         label = &m_label;
         return true;
     }
 
 private:
     const WebCryptoAlgorithm m_hash;
     const bool m_hasLabel;
     const WebVector<unsigned char> m_label;
 };
 
 } // namespace blink
 
 #endif