Revert "Remove MediaKeys.isTypeSupported()."

Source/modules/encryptedmedia/MediaKeys.h

 /*
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 39 matching lines @@
     virtual ~MediaKeys();
 
     // FIXME: This should be removed after crbug.com/425186 is fully
     // implemented.
     const String& keySystem() const { return m_keySystem; }
 
     MediaKeySession* createSession(ScriptState*, const String& sessionType);
 
     ScriptPromise setServerCertificate(ScriptState*, const DOMArrayPiece& serverCertificate);
 
+    // FIXME: Remove this method since it's not in the spec anymore.
+    static bool isTypeSupported(const String& keySystem, const String& contentType);
+
     blink::WebContentDecryptionModule* contentDecryptionModule();
 
     void trace(Visitor*);
 
     // ContextLifecycleObserver
     virtual void contextDestroyed() override;
 
 private:
     class PendingAction;
 
     void timerFired(Timer<MediaKeys>*);
 
     const String m_keySystem;
     OwnPtr<blink::WebContentDecryptionModule> m_cdm;
 
     HeapDeque<Member<PendingAction> > m_pendingActions;
     Timer<MediaKeys> m_timer;
 };
 
 } // namespace blink
 
 #endif // MediaKeys_h