Remove unused TransformOperation::isIdentity

Source/platform/transforms/SkewTransformOperation.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 23 matching lines @@
     static PassRefPtr<SkewTransformOperation> create(double angleX, double angleY, OperationType type)
     {
         return adoptRef(new SkewTransformOperation(angleX, angleY, type));
     }
 
     double angleX() const { return m_angleX; }
     double angleY() const { return m_angleY; }
 
     virtual bool canBlendWith(const TransformOperation& other) const;
 private:
-    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 OVERRIDE
     {
         if (!isSameType(o))
             return false;
         const SkewTransformOperation* s = static_cast<const SkewTransformOperation*>(&o);
         return m_angleX == s->m_angleX && m_angleY == s->m_angleY;
     }
 
@@ skipping 12 matching lines @@
     }
 
     double m_angleX;
     double m_angleY;
     OperationType m_type;
 };
 
 } // namespace blink
 
 #endif // SkewTransformOperation_h