Replacing the 'return 0;' statements with 'return nullptr;'

public/platform/WebCrypto.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 198 matching lines @@
     virtual void deriveBits(const WebCryptoAlgorithm&, const WebCryptoKey&, unsigned length, WebCryptoResult result) { result.completeWithError(WebCryptoErrorTypeNotSupported, ""); }
     virtual void deriveKey(const WebCryptoAlgorithm& algorithm, const WebCryptoKey& baseKey, const WebCryptoAlgorithm& importAlgorithm, const WebCryptoAlgorithm& keyLengthAlgorithm, bool extractable, WebCryptoKeyUsageMask, WebCryptoResult result) { result.completeWithError(WebCryptoErrorTypeNotSupported, ""); }
 
     // This is the exception to the "Completing the request" guarantees
     // outlined above. This is useful for Blink internal crypto and is not part
     // of the WebCrypto standard. createDigestor must provide the result via
     // the WebCryptoDigestor object synchronously. createDigestor may return 0
     // if it fails to create a WebCryptoDigestor. If it succeeds, the
     // WebCryptoDigestor returned by createDigestor must be freed by the
     // caller.
-    virtual WebCryptoDigestor* createDigestor(WebCryptoAlgorithmId algorithmId) { return 0; }
+    virtual WebCryptoDigestor* createDigestor(WebCryptoAlgorithmId algorithmId) { return nullptr; }
 
     // -----------------------
     // Structured clone
     // -----------------------
     //
     // deserializeKeyForClone() and serializeKeyForClone() are used for
     // implementing structured cloning of WebCryptoKey.
     //
     // Blink is responsible for saving and restoring all of the attributes of
     // WebCryptoKey EXCEPT for the actual key data:
@@ skipping 36 matching lines @@
     // Returns true on success.
     virtual bool serializeKeyForClone(const WebCryptoKey&, WebVector<unsigned char>&) { return false; }
 
 protected:
     virtual ~WebCrypto() { }
 };
 
 } // namespace blink
 
 #endif // WebCrypto_h