Expose CryptoKey everywhere if context is secure

Required for SubtleCrypto.

Author: ptomato

spec/Overview.html

@@ -1054,7 +1054,7 @@ <h2>CryptoKey interface</h2>
 
 enum KeyUsage { "encrypt", "decrypt", "sign", "verify", "deriveKey", "deriveBits", "wrapKey", "unwrapKey" };
 
-[SecureContext,Exposed=(Window,Worker),Serializable]
+[SecureContext,Exposed=*,Serializable]
 interface CryptoKey {
   readonly attribute KeyType type;
   readonly attribute boolean extractable;