Remove unused TransformOperation::isIdentity

Source/platform/transforms/InterpolatedTransformOperation.h

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 32 matching lines @@
     {
         return adoptRef(new InterpolatedTransformOperation(from, to, progress));
     }
 
     virtual bool canBlendWith(const TransformOperation& other) const
     {
         return isSameType(other);
     }
 
 private:
-    virtual bool isIdentity() const OVERRIDE { return false; }
-
     virtual OperationType type() const OVERRIDE { return Interpolated; }
 
     virtual bool operator==(const TransformOperation&) const OVERRIDE;
     virtual void apply(TransformationMatrix&, const FloatSize& borderBoxSize) const OVERRIDE;
 
     virtual PassRefPtr<TransformOperation> blend(const TransformOperation* from, double progress, bool blendToIdentity = false) OVERRIDE;
 
     virtual bool dependsOnBoxSize() const OVERRIDE
     {
         return from.dependsOnBoxSize() || to.dependsOnBoxSize();
     }
 
     InterpolatedTransformOperation(const TransformOperations& from, const TransformOperations& to, double progress)
         : from(from)
         , to(to)
         , progress(progress)
     { }
 
     const TransformOperations from;
     const TransformOperations to;
     double progress;
 };
 
 } // namespace blink
 
 #endif // InterpolatedTransformOperation_h