[webcrypto] Add the KeyAlgorithm interface.

Source/modules/crypto/AesKeyAlgorithm.cpp

Index: Source/modules/crypto/AesKeyAlgorithm.cpp
diff --git a/Source/modules/crypto/Algorithm.cpp b/Source/modules/crypto/AesKeyAlgorithm.cpp
similarity index 74%
copy from Source/modules/crypto/Algorithm.cpp
copy to Source/modules/crypto/AesKeyAlgorithm.cpp
index 35568ff46e53cd840dc945fad6df50f12beff7be..1fc8188b8e5fc2528cae7813989b42ee2e525ef4 100644
--- a/Source/modules/crypto/Algorithm.cpp
+++ b/Source/modules/crypto/AesKeyAlgorithm.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Google Inc. All rights reserved.
+ * Copyright (C) 2014 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
@@ -29,27 +29,33 @@
  */
 
 #include "config.h"
-#include "modules/crypto/Algorithm.h"
+#include "modules/crypto/AesKeyAlgorithm.h"
 
 #include "modules/crypto/NormalizeAlgorithm.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
-PassRefPtrWillBeRawPtr<Algorithm> Algorithm::create(const blink::WebCryptoAlgorithm& algorithm)
+PassRefPtrWillBeRawPtr<AesKeyAlgorithm> AesKeyAlgorithm::create(const blink::WebCryptoKeyAlgorithm& algorithm)
 {
-    return adoptRefWillBeNoop(new Algorithm(algorithm));
+    return adoptRefWillBeNoop(new AesKeyAlgorithm(algorithm));
 }
 
-Algorithm::Algorithm(const blink::WebCryptoAlgorithm& algorithm)
-    : m_algorithm(algorithm)
+unsigned short AesKeyAlgorithm::length()
 {
-    ScriptWrappable::init(this);
+    return m_algorithm.aesParams()->lengthBits();
 }
 
-String Algorithm::name()
+void AesKeyAlgorithm::trace(Visitor* visitor)
 {
-    return algorithmIdToName(m_algorithm.id());
+    KeyAlgorithm::trace(visitor);
+}
+
+AesKeyAlgorithm::AesKeyAlgorithm(const blink::WebCryptoKeyAlgorithm& algorithm)
+    : KeyAlgorithm(algorithm)
+{
+    ASSERT(m_algorithm.aesParams());
+    ScriptWrappable::init(this);
 }
 
 } // namespace WebCore