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

Source/platform/graphics/GradientGeneratedImage.h

Index: Source/platform/graphics/GradientGeneratedImage.h
diff --git a/Source/platform/graphics/GradientGeneratedImage.h b/Source/platform/graphics/GradientGeneratedImage.h
index 729ba9d531c16af1a71ba12d27c8ceda4d2be083..e2e493a8fc8fc769778ab7888e1d6aa6364bf46b 100644
--- a/Source/platform/graphics/GradientGeneratedImage.h
+++ b/Source/platform/graphics/GradientGeneratedImage.h
@@ -42,9 +42,7 @@ public:
         return adoptRef(new GradientGeneratedImage(generator, size));
     }
 
-    virtual ~GradientGeneratedImage()
-    {
-    }
+    ~GradientGeneratedImage() override {}
 
 protected:
     void draw(SkCanvas*, const SkPaint&, const FloatRect&, const FloatRect&, RespectImageOrientationEnum, ImageClampingMode) override;