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

Source/modules/app_banner/BeforeInstallPromptEvent.h

Index: Source/modules/app_banner/BeforeInstallPromptEvent.h
diff --git a/Source/modules/app_banner/BeforeInstallPromptEvent.h b/Source/modules/app_banner/BeforeInstallPromptEvent.h
index c5fd15324ee23665d52d795555b05280cd3a8757..a28d0a55b894c197f2977210271bf028b80185eb 100644
--- a/Source/modules/app_banner/BeforeInstallPromptEvent.h
+++ b/Source/modules/app_banner/BeforeInstallPromptEvent.h
@@ -17,7 +17,7 @@ class WebAppBannerClient;
 class BeforeInstallPromptEvent final : public Event {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    virtual ~BeforeInstallPromptEvent();
+    ~BeforeInstallPromptEvent() override;
 
     // For EventModules.cpp
     static PassRefPtrWillBeRawPtr<BeforeInstallPromptEvent> create()
@@ -38,7 +38,7 @@ public:
     Vector<String> platforms() const;
     ScriptPromise userChoice(ScriptState*);
 
-    virtual const AtomicString& interfaceName() const override;
+    const AtomicString& interfaceName() const override;
 
     ScriptPromise prompt(ScriptState*);