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

Source/platform/exported/WebScrollbarImpl.h

Index: Source/platform/exported/WebScrollbarImpl.h
diff --git a/Source/platform/exported/WebScrollbarImpl.h b/Source/platform/exported/WebScrollbarImpl.h
index 7c865107c78e09929a0082036c9bd82c5334245e..f3e875a63f01633772c17bc625e433dabe948e43 100644
--- a/Source/platform/exported/WebScrollbarImpl.h
+++ b/Source/platform/exported/WebScrollbarImpl.h
@@ -40,26 +40,26 @@ public:
     }
 
     // Implement WebScrollbar methods
-    virtual bool isOverlay() const override;
-    virtual int value() const override;
-    virtual WebPoint location() const override;
-    virtual WebSize size() const override;
-    virtual bool enabled() const override;
-    virtual int maximum() const override;
-    virtual int totalSize() const override;
-    virtual bool isScrollableAreaActive() const override;
-    virtual void getTickmarks(WebVector<WebRect>& tickmarks) const override;
-    virtual ScrollbarControlSize controlSize() const override;
-    virtual ScrollbarPart pressedPart() const override;
-    virtual ScrollbarPart hoveredPart() const override;
-    virtual ScrollbarOverlayStyle scrollbarOverlayStyle() const override;
-    virtual bool isCustomScrollbar() const override;
-    virtual Orientation orientation() const override;
-    virtual bool isLeftSideVerticalScrollbar() const override;
-    virtual bool isAlphaLocked() const override;
-    virtual void setIsAlphaLocked(bool) override;
-    virtual float elasticOverscroll() const override;
-    virtual void setElasticOverscroll(float) override;
+    bool isOverlay() const override;
+    int value() const override;
+    WebPoint location() const override;
+    WebSize size() const override;
+    bool enabled() const override;
+    int maximum() const override;
+    int totalSize() const override;
+    bool isScrollableAreaActive() const override;
+    void getTickmarks(WebVector<WebRect>& tickmarks) const override;
+    ScrollbarControlSize controlSize() const override;
+    ScrollbarPart pressedPart() const override;
+    ScrollbarPart hoveredPart() const override;
+    ScrollbarOverlayStyle scrollbarOverlayStyle() const override;
+    bool isCustomScrollbar() const override;
+    Orientation orientation() const override;
+    bool isLeftSideVerticalScrollbar() const override;
+    bool isAlphaLocked() const override;
+    void setIsAlphaLocked(bool) override;
+    float elasticOverscroll() const override;
+    void setElasticOverscroll(float) override;
 
 private:
     explicit WebScrollbarImpl(Scrollbar*);