Fix virtual/override/final usage in Source/modules/.

Source/modules/encryptedmedia/MediaKeySystemAccess.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "modules/encryptedmedia/MediaKeySystemAccess.h"
 
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "core/dom/DOMException.h"
@@ skipping 23 matching lines @@
 class NewCdmResultPromise : public ContentDecryptionModuleResultPromise {
     WTF_MAKE_NONCOPYABLE(NewCdmResultPromise);
 
 public:
     NewCdmResultPromise(ScriptState* scriptState, const WebVector<WebEncryptedMediaSessionType>& supportedSessionTypes)
         : ContentDecryptionModuleResultPromise(scriptState)
         , m_supportedSessionTypes(supportedSessionTypes)
     {
     }
 
-    virtual ~NewCdmResultPromise()
+    ~NewCdmResultPromise() override
     {
     }
 
     // ContentDecryptionModuleResult implementation.
-    virtual void completeWithContentDecryptionModule(WebContentDecryptionModule* cdm) override
+    void completeWithContentDecryptionModule(WebContentDecryptionModule* cdm) override
     {
         // NOTE: Continued from step 2.8 of createMediaKeys().
         // 2.9. Let media keys be a new MediaKeys object.
         MediaKeys* mediaKeys = MediaKeys::create(executionContext(), m_supportedSessionTypes, adoptPtr(cdm));
 
         // 2.10. Resolve promise with media keys.
         resolve(mediaKeys);
     }
 
 private:
@@ skipping 106 matching lines @@
 
     // 3. Return promise.
     return promise;
 }
 
 DEFINE_TRACE(MediaKeySystemAccess)
 {
 }
 
 } // namespace blink