Reapply the non-MathExtras parts of

Source/platform/transforms/PerspectiveTransformOperation.cpp

 /*
  * 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 20 matching lines @@
 
 namespace blink {
 
 PassRefPtr<TransformOperation> PerspectiveTransformOperation::blend(const TransformOperation* from, double progress, bool blendToIdentity)
 {
     if (from && !from->isSameType(*this))
         return this;
 
     if (blendToIdentity) {
         double p = blink::blend(m_p, 1., progress); // FIXME: this seems wrong. https://bugs.webkit.org/show_bug.cgi?id=52700
-        return PerspectiveTransformOperation::create(clampToPositiveInteger(p));
+        return PerspectiveTransformOperation::create(clampTo<int>(p, 0));
     }
 
     const PerspectiveTransformOperation* fromOp = static_cast<const PerspectiveTransformOperation*>(from);
 
     TransformationMatrix fromT;
     TransformationMatrix toT;
     fromT.applyPerspective(fromOp ? fromOp->m_p : 0);
     toT.applyPerspective(m_p);
     toT.blend(fromT, progress);
     TransformationMatrix::DecomposedType decomp;
     toT.decompose(decomp);
 
     if (decomp.perspectiveZ) {
         double val = -1.0 / decomp.perspectiveZ;
-        return PerspectiveTransformOperation::create(clampToPositiveInteger(val));
+        return PerspectiveTransformOperation::create(clampTo<int>(val, 0));
     }
     return PerspectiveTransformOperation::create(0);
 }
 
 } // namespace blink