[webcrypto] Implement structured clone of keys (blink-side).

public/platform/WebCryptoKeyAlgorithm.h

Index: public/platform/WebCryptoKeyAlgorithm.h
diff --git a/public/platform/WebCryptoKeyAlgorithm.h b/public/platform/WebCryptoKeyAlgorithm.h
index d35e71561d9c68c62c65385d66d6a11f7ca2c025..5ca535474d64bca34bb453a6744c7ad32741dc16 100644
--- a/public/platform/WebCryptoKeyAlgorithm.h
+++ b/public/platform/WebCryptoKeyAlgorithm.h
@@ -56,8 +56,14 @@ public:
     BLINK_PLATFORM_EXPORT WebCryptoKeyAlgorithm(WebCryptoAlgorithmId, PassOwnPtr<WebCryptoKeyAlgorithmParams>);
 #endif
 
+    // FIXME: Delete this in favor of the create*() functions.
     BLINK_PLATFORM_EXPORT static WebCryptoKeyAlgorithm adoptParamsAndCreate(WebCryptoAlgorithmId, WebCryptoKeyAlgorithmParams*);
 
+    BLINK_PLATFORM_EXPORT static WebCryptoKeyAlgorithm createAes(WebCryptoAlgorithmId, unsigned short keyLengthBits);
+    BLINK_PLATFORM_EXPORT static WebCryptoKeyAlgorithm createHmac(WebCryptoAlgorithmId hash);
+    BLINK_PLATFORM_EXPORT static WebCryptoKeyAlgorithm createRsa(WebCryptoAlgorithmId, unsigned modulusLengthBits, const unsigned char* publicExponent, unsigned publicExponentSize);
+    BLINK_PLATFORM_EXPORT static WebCryptoKeyAlgorithm createRsaHashed(WebCryptoAlgorithmId, unsigned modulusLengthBits, const unsigned char* publicExponent, unsigned publicExponentSize, WebCryptoAlgorithmId hash);
+
     ~WebCryptoKeyAlgorithm() { reset(); }
 
     WebCryptoKeyAlgorithm(const WebCryptoKeyAlgorithm& other) { assign(other); }