Rewrite NaN checks in terms of SkScalarIsNaN()

include/core/SkPoint.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPoint_DEFINED
 #define SkPoint_DEFINED
 
@@ skipping 339 matching lines @@
 
     /**
      *  Returns true if both X and Y are finite (not infinity or NaN)
      */
     bool isFinite() const {
         SkScalar accum = 0;
         accum *= fX;
         accum *= fY;
 
         // accum is either NaN or it is finite (zero).
-        SkASSERT(0 == accum || !(accum == accum));
+        SkASSERT(0 == accum || SkScalarIsNaN(accum));
 
         // value==value will be true iff value is not NaN
         // TODO: is it faster to say !accum or accum==accum?
-        return accum == accum;
+        return !SkScalarIsNaN(accum);
     }
 
     /**
      *  Returns true if the point's coordinates equal (x,y)
      */
     bool equals(SkScalar x, SkScalar y) const {
         return fX == x && fY == y;
     }
 
     friend bool operator==(const SkPoint& a, const SkPoint& b) {
@@ skipping 158 matching lines @@
 
     /**
      *  cast-safe way to treat the point as an array of (2) SkScalars.
      */
     const SkScalar* asScalars() const { return &fX; }
 };
 
 typedef SkPoint SkVector;
 
 #endif