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

Source/platform/scroll/ScrollbarThemeAura.h

Index: Source/platform/scroll/ScrollbarThemeAura.h
diff --git a/Source/platform/scroll/ScrollbarThemeAura.h b/Source/platform/scroll/ScrollbarThemeAura.h
index aa8b4140be9f32e0b1ebec0ac94adaa2c2b84c17..9a0fbec2c04bc47da4428590dfaeb4632c858574 100644
--- a/Source/platform/scroll/ScrollbarThemeAura.h
+++ b/Source/platform/scroll/ScrollbarThemeAura.h
@@ -37,14 +37,14 @@ namespace blink {
 
 class PLATFORM_EXPORT ScrollbarThemeAura : public ScrollbarThemeNonMacCommon {
 public:
-    virtual int scrollbarThickness(ScrollbarControlSize) override;
+    int scrollbarThickness(ScrollbarControlSize) override;
 
 protected:
-    virtual void paintTrackPiece(GraphicsContext*, ScrollbarThemeClient*, const IntRect&, ScrollbarPart) override;
-    virtual void paintButton(GraphicsContext*, ScrollbarThemeClient*, const IntRect&, ScrollbarPart) override;
-    virtual void paintThumb(GraphicsContext*, ScrollbarThemeClient*, const IntRect&) override;
-    virtual IntSize buttonSize(ScrollbarThemeClient*) override;
-    virtual int minimumThumbLength(ScrollbarThemeClient*) override;
+    void paintTrackPiece(GraphicsContext*, ScrollbarThemeClient*, const IntRect&, ScrollbarPart) override;
+    void paintButton(GraphicsContext*, ScrollbarThemeClient*, const IntRect&, ScrollbarPart) override;
+    void paintThumb(GraphicsContext*, ScrollbarThemeClient*, const IntRect&) override;
+    IntSize buttonSize(ScrollbarThemeClient*) override;
+    int minimumThumbLength(ScrollbarThemeClient*) override;
 };
 
 } // namespace blink