WebCrypto: Add interfaces for importKey().

Source/modules/crypto/Key.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 28 matching lines @@
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 class Algorithm;
 
 class Key : public ScriptWrappable, public RefCounted<Key> {
 public:
     static PassRefPtr<Key> create(const WebKit::WebCryptoKey& key) { return adoptRef(new Key(key)); }
 
+    ~Key();
+
     String type() const;
     bool extractable() const;
     Algorithm* algorithm();
     Vector<String> usages() const;
 
+    static bool parseFormat(const String&, WebKit::WebCryptoKeyFormat&);
+
+    // Parses KeyUsage strings to a WebCryptoKeyUsageMask. If any element is
+    // unrecognized, returns false.
+    static bool parseUsageMask(const Vector<String>&, WebKit::WebCryptoKeyUsageMask&);
+
 protected:
     explicit Key(const WebKit::WebCryptoKey&);
 
     const WebKit::WebCryptoKey m_key;
     RefPtr<Algorithm> m_algorithm;
 };
 
 } // namespace WebCore
 
 #endif