[webcrypto] Add the KeyAlgorithm interface.

public/platform/WebCryptoKey.h

Index: public/platform/WebCryptoKey.h
diff --git a/public/platform/WebCryptoKey.h b/public/platform/WebCryptoKey.h
index eea6bb2db72d0a180f9085b19ad7dd49b7b16806..8a48e6b8902a9d21ab82bd62b7d71db8c208be81 100644
--- a/public/platform/WebCryptoKey.h
+++ b/public/platform/WebCryptoKey.h
@@ -65,7 +65,7 @@ enum WebCryptoKeyFormat {
     WebCryptoKeyFormatJwk,
 };
 
-class WebCryptoAlgorithm;
+class WebCryptoKeyAlgorithm;
 class WebCryptoKeyPrivate;
 class WebCryptoKeyHandle;
 
@@ -106,7 +106,7 @@ public:
     // https://dvcs.w3.org/hg/webcrypto-api/raw-file/tip/spec/Overview.html#key-interface-members
     //
     // Note that the caller is passing ownership of the WebCryptoKeyHandle*.
-    BLINK_PLATFORM_EXPORT static WebCryptoKey create(WebCryptoKeyHandle*, WebCryptoKeyType, bool extractable, const WebCryptoAlgorithm&, WebCryptoKeyUsageMask);
+    BLINK_PLATFORM_EXPORT static WebCryptoKey create(WebCryptoKeyHandle*, WebCryptoKeyType, bool extractable, const WebCryptoKeyAlgorithm&, WebCryptoKeyUsageMask);
 
     BLINK_PLATFORM_EXPORT static WebCryptoKey createNull();
 
@@ -117,7 +117,7 @@ public:
 
     BLINK_PLATFORM_EXPORT WebCryptoKeyType type() const;
     BLINK_PLATFORM_EXPORT bool extractable() const;
-    BLINK_PLATFORM_EXPORT const WebCryptoAlgorithm& algorithm() const;
+    BLINK_PLATFORM_EXPORT const WebCryptoKeyAlgorithm& algorithm() const;
     BLINK_PLATFORM_EXPORT WebCryptoKeyUsageMask usages() const;
 
     BLINK_PLATFORM_EXPORT bool isNull() const;