Fix virtual/override/final usage in the rest of Source/core/.

Source/core/imagebitmap/ImageBitmapFactories.h

Index: Source/core/imagebitmap/ImageBitmapFactories.h
diff --git a/Source/core/imagebitmap/ImageBitmapFactories.h b/Source/core/imagebitmap/ImageBitmapFactories.h
index 5de8f8b8ea7871c78da56d9149f78867659f8786..401360ac8accc646b28ed0493aaa9e4be573ec08 100644
--- a/Source/core/imagebitmap/ImageBitmapFactories.h
+++ b/Source/core/imagebitmap/ImageBitmapFactories.h
@@ -81,7 +81,7 @@ private:
 
         DECLARE_TRACE();
 
-        virtual ~ImageBitmapLoader() { }
+        ~ImageBitmapLoader() override { }
 
     private:
         ImageBitmapLoader(ImageBitmapFactories&, const IntRect&, ScriptState*);
@@ -89,10 +89,10 @@ private:
         void rejectPromise();
 
         // FileReaderLoaderClient
-        virtual void didStartLoading() override { }
-        virtual void didReceiveData() override { }
-        virtual void didFinishLoading() override;
-        virtual void didFail(FileError::ErrorCode) override;
+        void didStartLoading() override { }
+        void didReceiveData() override { }
+        void didFinishLoading() override;
+        void didFail(FileError::ErrorCode) override;
 
         FileReaderLoader m_loader;
         RawPtrWillBeMember<ImageBitmapFactories> m_factory;