let line/cubic intersect at four spots

src/pathops/SkDCubicLineIntersection.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkIntersections.h"
 #include "SkPathOpsCubic.h"
 #include "SkPathOpsCurve.h"
 #include "SkPathOpsLine.h"
@@ skipping 69 matching lines @@
     enum PinTPoint {
         kPointUninitialized,
         kPointInitialized
     };
 
     LineCubicIntersections(const SkDCubic& c, const SkDLine& l, SkIntersections* i)
         : fCubic(c)
         , fLine(l)
         , fIntersections(i)
         , fAllowNear(true) {
-        i->setMax(3);
+        i->setMax(4);
     }
 
     void allowNear(bool allow) {
         fAllowNear = allow;
     }
 
     void checkCoincident() {
         int last = fIntersections->used() - 1;
         for (int index = 0; index < last; ) {
             double cubicMidT = ((*fIntersections)[0][index] + (*fIntersections)[0][index + 1]) / 2;
@@ skipping 344 matching lines @@
 
 // SkDCubic accessors to Intersection utilities
 
 int SkDCubic::horizontalIntersect(double yIntercept, double roots[3]) const {
     return LineCubicIntersections::HorizontalIntersect(*this, yIntercept, roots);
 }
 
 int SkDCubic::verticalIntersect(double xIntercept, double roots[3]) const {
     return LineCubicIntersections::VerticalIntersect(*this, xIntercept, roots);
 }