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

Source/core/animation/animatable/AnimatableVisibility.h

Index: Source/core/animation/animatable/AnimatableVisibility.h
diff --git a/Source/core/animation/animatable/AnimatableVisibility.h b/Source/core/animation/animatable/AnimatableVisibility.h
index a70c84e99f02ad6bd7576f19879f00368a3ef0f6..f52993467de9360e27a55604dcfa3f4e92680845 100644
--- a/Source/core/animation/animatable/AnimatableVisibility.h
+++ b/Source/core/animation/animatable/AnimatableVisibility.h
@@ -39,7 +39,7 @@ namespace blink {
 
 class CORE_EXPORT AnimatableVisibility final : public AnimatableValue {
 public:
-    virtual ~AnimatableVisibility() { }
+    ~AnimatableVisibility() override { }
     static PassRefPtrWillBeRawPtr<AnimatableVisibility> create(EVisibility visibility)
     {
         return adoptRefWillBeNoop(new AnimatableVisibility(visibility));
@@ -50,16 +50,16 @@ public:
     DEFINE_INLINE_VIRTUAL_TRACE() { AnimatableValue::trace(visitor); }
 
 protected:
-    virtual PassRefPtrWillBeRawPtr<AnimatableValue> interpolateTo(const AnimatableValue*, double fraction) const override;
-    virtual bool usesDefaultInterpolationWith(const AnimatableValue*) const override;
+    PassRefPtrWillBeRawPtr<AnimatableValue> interpolateTo(const AnimatableValue*, double fraction) const override;
+    bool usesDefaultInterpolationWith(const AnimatableValue*) const override;
 
 private:
     explicit AnimatableVisibility(EVisibility visibility)
         : m_visibility(visibility)
     {
     }
-    virtual AnimatableType type() const override { return TypeVisibility; }
-    virtual bool equalTo(const AnimatableValue*) const override;
+    AnimatableType type() const override { return TypeVisibility; }
+    bool equalTo(const AnimatableValue*) const override;
     const EVisibility m_visibility;
 };