Update platform classes to use OVERRIDE / FINAL when needed

Source/platform/transforms/SkewTransformOperation.h

Index: Source/platform/transforms/SkewTransformOperation.h
diff --git a/Source/platform/transforms/SkewTransformOperation.h b/Source/platform/transforms/SkewTransformOperation.h
index 4b90ee09d69a489d28c1a601c105e84b8a942a4b..1865deb2f3a2734cb6b5e68f8702b0c833ecee1d 100644
--- a/Source/platform/transforms/SkewTransformOperation.h
+++ b/Source/platform/transforms/SkewTransformOperation.h
@@ -40,7 +40,7 @@ public:
     double angleY() const { return m_angleY; }
 
 private:
-    virtual bool isIdentity() const { return m_angleX == 0 && m_angleY == 0; }
+    virtual bool isIdentity() const OVERRIDE { return !m_angleX && !m_angleY; }
     virtual OperationType type() const OVERRIDE { return m_type; }
 
     virtual bool operator==(const TransformOperation& o) const
@@ -51,12 +51,12 @@ private:
         return m_angleX == s->m_angleX && m_angleY == s->m_angleY;
     }
 
-    virtual void apply(TransformationMatrix& transform, const FloatSize&) const
+    virtual void apply(TransformationMatrix& transform, const FloatSize&) const OVERRIDE
     {
         transform.skew(m_angleX, m_angleY);
     }
 
-    virtual PassRefPtr<TransformOperation> blend(const TransformOperation* from, double progress, bool blendToIdentity = false);
+    virtual PassRefPtr<TransformOperation> blend(const TransformOperation* from, double progress, bool blendToIdentity = false) OVERRIDE;
 
     SkewTransformOperation(double angleX, double angleY, OperationType type)
         : m_angleX(angleX)