[webcrypto] Add the KeyAlgorithm interface.

Source/modules/crypto/Key.h

Index: Source/modules/crypto/Key.h
diff --git a/Source/modules/crypto/Key.h b/Source/modules/crypto/Key.h
index 6937c14a82bc07b5655be0ee83edf72b8642c317..d2f47512c5c2aabdf9c6b665bc631f8110ef3656 100644
--- a/Source/modules/crypto/Key.h
+++ b/Source/modules/crypto/Key.h
@@ -42,10 +42,10 @@
 
 namespace WebCore {
 
-class Algorithm;
 class CryptoResult;
+class KeyAlgorithm;
 
-class Key : public RefCountedWillBeGarbageCollectedFinalized<Key>,  public ScriptWrappable {
+class Key : public RefCountedWillBeGarbageCollectedFinalized<Key>, public ScriptWrappable {
     DECLARE_GC_INFO;
 public:
     static PassRefPtrWillBeRawPtr<Key> create(const blink::WebCryptoKey& key)
@@ -57,7 +57,7 @@ public:
 
     String type() const;
     bool extractable() const;
-    Algorithm* algorithm();
+    KeyAlgorithm* algorithm();
     Vector<String> usages() const;
 
     const blink::WebCryptoKey& key() const { return m_key; }
@@ -76,7 +76,7 @@ protected:
     explicit Key(const blink::WebCryptoKey&);
 
     const blink::WebCryptoKey m_key;
-    RefPtrWillBeMember<Algorithm> m_algorithm;
+    RefPtrWillBeMember<KeyAlgorithm> m_algorithm;
 };
 
 } // namespace WebCore