[webcrypto] Make WebCryptoAlgorithm "nullable".

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 38 matching lines @@
     explicit WebCryptoAlgorithmParams(WebCryptoAlgorithmParamsType type)
         : m_type(type)
     {
     }
 
     virtual ~WebCryptoAlgorithmParams() { }
 
     WebCryptoAlgorithmParamsType type() const { return m_type; }
 
 private:
-    WebCryptoAlgorithmParamsType m_type;
+    const WebCryptoAlgorithmParamsType m_type;
 };
 
 class WebCryptoAesCbcParams : public WebCryptoAlgorithmParams {
 public:
     WebCryptoAesCbcParams(const unsigned char* iv, unsigned ivSize)
         : WebCryptoAlgorithmParams(WebCryptoAlgorithmParamsTypeAesCbcParams)
         , m_iv(iv, ivSize)
     {
     }
 
@@ skipping 16 matching lines @@
 private:
     const unsigned short m_length;
 };
 
 class WebCryptoHmacParams : public WebCryptoAlgorithmParams {
 public:
     explicit WebCryptoHmacParams(const WebCryptoAlgorithm& hash)
         : WebCryptoAlgorithmParams(WebCryptoAlgorithmParamsTypeHmacParams)
         , m_hash(hash)
     {
+        BLINK_ASSERT(!hash.isNull());
     }
 
     const WebCryptoAlgorithm& hash() const { return m_hash; }
 
 private:
-    WebCryptoAlgorithm m_hash;
+    const WebCryptoAlgorithm m_hash;
 };
 
 class WebCryptoHmacKeyParams : public WebCryptoAlgorithmParams {
 public:
     WebCryptoHmacKeyParams(const WebCryptoAlgorithm& hash, bool hasLength, unsigned length)
         : WebCryptoAlgorithmParams(WebCryptoAlgorithmParamsTypeHmacKeyParams)
         , m_hash(hash)
         , m_hasLength(hasLength)
         , m_length(length)
     {
+        BLINK_ASSERT(!hash.isNull());
     }
 
     const WebCryptoAlgorithm& hash() const { return m_hash; }
 
     bool hasLength() const { return m_hasLength; }
 
     bool getLength(unsigned& length) const
     {
         if (!m_hasLength)
             return false;
         length = m_length;
         return true;
     }
 
 private:
-    WebCryptoAlgorithm m_hash;
-    bool m_hasLength;
-    unsigned m_length;
+    const WebCryptoAlgorithm m_hash;
+    const bool m_hasLength;
+    const unsigned m_length;
 };
 
 class WebCryptoRsaSsaParams : public WebCryptoAlgorithmParams {
 public:
     explicit WebCryptoRsaSsaParams(const WebCryptoAlgorithm& hash)
         : WebCryptoAlgorithmParams(WebCryptoAlgorithmParamsTypeRsaSsaParams)
         , m_hash(hash)
     {
+        BLINK_ASSERT(!hash.isNull());
     }
 
     const WebCryptoAlgorithm& hash() const { return m_hash; }
 
 private:
-    WebCryptoAlgorithm m_hash;
+    const WebCryptoAlgorithm m_hash;
 };
 
 class WebCryptoRsaKeyGenParams : public WebCryptoAlgorithmParams {
 public:
     WebCryptoRsaKeyGenParams(unsigned modulusLength, const unsigned char* publicExponent, unsigned publicExponentSize)
         : WebCryptoAlgorithmParams(WebCryptoAlgorithmParamsTypeRsaKeyGenParams)
         , m_modulusLength(modulusLength)
         , m_publicExponent(publicExponent, publicExponentSize)
     {
     }
@@ skipping 47 matching lines @@
 };
 
 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)
     {
         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 WebKit
 
 #endif