Fix assert in GPU path rendering found by fuzzer.

src/gpu/GrPathUtils.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrPathUtils.h"
 
 #include "GrTypes.h"
@@ skipping 28 matching lines @@
 uint32_t GrPathUtils::quadraticPointCount(const SkPoint points[],
                                           SkScalar tol) {
     if (tol < gMinCurveTol) {
         tol = gMinCurveTol;
     }
     SkASSERT(tol > 0);
 
     SkScalar d = points[1].distanceToLineSegmentBetween(points[0], points[2]);
     if (d <= tol) {
         return 1;
+    } else if (!SkScalarIsFinite(d)) {
+        return MAX_POINTS_PER_CURVE;
     } else {
         // Each time we subdivide, d should be cut in 4. So we need to
         // subdivide x = log4(d/tol) times. x subdivisions creates 2^(x)
         // points.
         // 2^(log4(x)) = sqrt(x);
         int temp = SkScalarCeilToInt(SkScalarSqrt(SkScalarDiv(d, tol)));
         int pow2 = GrNextPow2(temp);
         // Because of NaNs & INFs we can wind up with a degenerate temp
         // such that pow2 comes out negative. Also, our point generator
         // will always output at least one pt.
@@ skipping 35 matching lines @@
         tol = gMinCurveTol;
     }
     SkASSERT(tol > 0);
 
     SkScalar d = SkTMax(
         points[1].distanceToLineSegmentBetweenSqd(points[0], points[3]),
         points[2].distanceToLineSegmentBetweenSqd(points[0], points[3]));
     d = SkScalarSqrt(d);
     if (d <= tol) {
         return 1;
+    } else if (!SkScalarIsFinite(d)) {
+        return MAX_POINTS_PER_CURVE;
     } else {
         int temp = SkScalarCeilToInt(SkScalarSqrt(SkScalarDiv(d, tol)));
         int pow2 = GrNextPow2(temp);
         // Because of NaNs & INFs we can wind up with a degenerate temp
         // such that pow2 comes out negative. Also, our point generator
         // will always output at least one pt.
         if (pow2 < 1) {
             pow2 = 1;
         }
         return SkTMin(pow2, MAX_POINTS_PER_CURVE);
@@ skipping 684 matching lines @@
         set_loop_klm(d, controlK, controlL, controlM);
     } else if (kCusp_SkCubicType == cType) {
         SkASSERT(0.f == d[0]);
         set_cusp_klm(d, controlK, controlL, controlM);
     } else if (kQuadratic_SkCubicType == cType) {
         set_quadratic_klm(d, controlK, controlL, controlM);
     }
 
     calc_cubic_klm(p, controlK, controlL, controlM, klm, &klm[3], &klm[6]);
 }