Fix virtual/override/final usage in Source/core/{animation,css,style}/.

Source/core/css/CSSCanvasValue.h

Index: Source/core/css/CSSCanvasValue.h
diff --git a/Source/core/css/CSSCanvasValue.h b/Source/core/css/CSSCanvasValue.h
index 549dc8f70869e4aade779cb03cf8a20b394c98d9..4e15b7f9befe814fefd5542be805a764af347279 100644
--- a/Source/core/css/CSSCanvasValue.h
+++ b/Source/core/css/CSSCanvasValue.h
@@ -70,16 +70,16 @@ private:
     public:
         explicit CanvasObserverProxy(CSSCanvasValue* ownerValue) : m_ownerValue(ownerValue) { }
 
-        virtual void canvasChanged(HTMLCanvasElement* canvas, const FloatRect& changedRect) override
+        void canvasChanged(HTMLCanvasElement* canvas, const FloatRect& changedRect) override
         {
             m_ownerValue->canvasChanged(canvas, changedRect);
         }
-        virtual void canvasResized(HTMLCanvasElement* canvas) override
+        void canvasResized(HTMLCanvasElement* canvas) override
         {
             m_ownerValue->canvasResized(canvas);
         }
 #if !ENABLE(OILPAN)
-        virtual void canvasDestroyed(HTMLCanvasElement* canvas) override
+        void canvasDestroyed(HTMLCanvasElement* canvas) override
         {
             m_ownerValue->canvasDestroyed(canvas);
         }