Remove unused TransformOperation::isIdentity

Source/platform/transforms/Matrix3DTransformOperation.h

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 27 matching lines @@
     }
 
     TransformationMatrix matrix() const {return m_matrix; }
 
     virtual bool canBlendWith(const TransformOperation& other) const
     {
         return false;
     }
 
 private:
-    virtual bool isIdentity() const OVERRIDE { return m_matrix.isIdentity(); }
-
     virtual OperationType type() const OVERRIDE { return Matrix3D; }
 
     virtual bool operator==(const TransformOperation& o) const OVERRIDE
     {
         if (!isSameType(o))
             return false;
         const Matrix3DTransformOperation* m = static_cast<const Matrix3DTransformOperation*>(&o);
         return m_matrix == m->m_matrix;
     }
 
     virtual void apply(TransformationMatrix& transform, const FloatSize&) const OVERRIDE
     {
         transform.multiply(TransformationMatrix(m_matrix));
     }
 
     virtual PassRefPtr<TransformOperation> blend(const TransformOperation* from, double progress, bool blendToIdentity = false) OVERRIDE;
 
     Matrix3DTransformOperation(const TransformationMatrix& mat)
     {
         m_matrix = mat;
     }
 
     TransformationMatrix m_matrix;
 };
 
 } // namespace blink
 
 #endif // Matrix3DTransformOperation_h