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

Source/core/animation/animatable/AnimatableDouble.h

Index: Source/core/animation/animatable/AnimatableDouble.h
diff --git a/Source/core/animation/animatable/AnimatableDouble.h b/Source/core/animation/animatable/AnimatableDouble.h
index a37d0c836f14bb488cf2d69937e539d0ecee4bc2..ae765dc6ed2ea260f796fa83de02120b797eb490 100644
--- a/Source/core/animation/animatable/AnimatableDouble.h
+++ b/Source/core/animation/animatable/AnimatableDouble.h
@@ -38,7 +38,7 @@ namespace blink {
 
 class CORE_EXPORT AnimatableDouble final : public AnimatableValue {
 public:
-    virtual ~AnimatableDouble() { }
+    ~AnimatableDouble() override { }
 
     enum Constraint {
         Unconstrained,
@@ -55,8 +55,8 @@ 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:
     AnimatableDouble(double number, Constraint constraint)
@@ -64,8 +64,8 @@ private:
         , m_constraint(constraint)
     {
     }
-    virtual AnimatableType type() const override { return TypeDouble; }
-    virtual bool equalTo(const AnimatableValue*) const override;
+    AnimatableType type() const override { return TypeDouble; }
+    bool equalTo(const AnimatableValue*) const override;
 
     double m_number;
     Constraint m_constraint;