Use nextafter instead of nexttoward to avoid using long double calculation.

src/core/SkScaleToSides.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkScaleToSides_DEFINED
 #define SkScaleToSides_DEFINED
 
@@ skipping 27 matching lines @@
             // is 1/2 the ratio of minRadius : (minRadius + maxRadius), therefore in the resulting
             // division, minRadius can be no larger than 1/2 limit + ULP.
             float newMinRadius = *minRadius;
 
             // Because newMaxRadius is the result of a double to float conversion, it can be larger
             // than limit, but only by one ULP.
             float newMaxRadius = (float)(limit - newMinRadius);
 
             // If newMaxRadius forces the total over the limit, then it needs to be
             // reduced by one ULP to be less than limit - newMinRadius.
-            // Note: nexttowardf is a c99 call and should be std::nexttoward, but this is not
-            // implemented in the ARM compiler.
+            // Note: nextafterf is a c99 call and should be std::nextafter, but this is not
+            // implemented in the GCC ARM compiler.
             if (newMaxRadius + newMinRadius > limit) {
-                newMaxRadius = nexttowardf(newMaxRadius, 0.0);
+                newMaxRadius = nextafterf(newMaxRadius, 0.0f);
             }
             *maxRadius = newMaxRadius;
         }
 
         SkASSERTF(*a >= 0.0f && *b >= 0.0f, "a: %g, b: %g, limit: %g, scale: %g", *a, *b, limit,
                   scale);
         SkASSERTF(*a + *b <= limit, "\nlimit: %.10f, a: %.10f, b: %.10f, scale: %.20f",
                   limit, *a, *b, scale);
     }
 };
 #endif // ScaleToSides_DEFINED