Update modules classes to use OVERRIDE / FINAL when needed

Source/modules/encryptedmedia/MediaKeySession.h

Index: Source/modules/encryptedmedia/MediaKeySession.h
diff --git a/Source/modules/encryptedmedia/MediaKeySession.h b/Source/modules/encryptedmedia/MediaKeySession.h
index 45072199301fd42012c494d5aba33a931f055356..586281722d4c18f83e034f0d5d40664449feeaa4 100644
--- a/Source/modules/encryptedmedia/MediaKeySession.h
+++ b/Source/modules/encryptedmedia/MediaKeySession.h
@@ -50,13 +50,13 @@ class MediaKeys;
 // Because this object controls the lifetime of the ContentDecryptionModuleSession,
 // it may outlive any references to it as long as the MediaKeys object is alive.
 // The ContentDecryptionModuleSession has the same lifetime as this object.
-class MediaKeySession
+class MediaKeySession FINAL
     : public RefCounted<MediaKeySession>, public ScriptWrappable, public EventTargetWithInlineData, public ContextLifecycleObserver
     , private ContentDecryptionModuleSessionClient {
     REFCOUNTED_EVENT_TARGET(MediaKeySession);
 public:
     static PassRefPtr<MediaKeySession> create(ExecutionContext*, ContentDecryptionModule*, MediaKeys*);
-    ~MediaKeySession();
+    virtual ~MediaKeySession();
 
     const String& keySystem() const { return m_keySystem; }
     String sessionId() const;