add more conservative check for wayward divide

gm/strokes.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 "gm.h"
 #include "SkPath.h"
 #include "SkRandom.h"
@@ skipping 175 matching lines @@
         line(0.00005f, canvas, SK_ColorBLACK);
         line(0.000045f, canvas, SK_ColorRED);
         line(0.0000035f, canvas, SK_ColorGREEN);
         line(0.000003f, canvas, SK_ColorBLUE);
         line(0.000002f, canvas, SK_ColorBLACK);
     }
 private:
     typedef skiagm::GM INHERITED;
 };
 
+DEF_SIMPLE_GM(CubicStroke, canvas, 384, 384) {
+    SkPaint p;
+    p.setAntiAlias(true);
+    p.setStyle(SkPaint::kStroke_Style);
+    p.setStrokeWidth(1.0720f);
+        SkPath path;
+    path.moveTo(-6000,-6000);
+    path.cubicTo(-3500,5500,-500,5500,2500,-6500);
+    canvas->drawPath(path, p);
+    p.setStrokeWidth(1.0721f);
+    canvas->translate(10, 10);
+    canvas->drawPath(path, p);
+    p.setStrokeWidth(1.0722f);
+    canvas->translate(10, 10);
+    canvas->drawPath(path, p);
+}
 
 class Strokes2GM : public skiagm::GM {
     SkPath fPath;
 protected:
     void onOnceBeforeDraw() override {
         SkRandom rand;
         fPath.moveTo(0, 0);
         for (int i = 0; i < 13; i++) {
             SkScalar x = rand.nextUScalar1() * (W >> 1);
             SkScalar y = rand.nextUScalar1() * (H >> 1);
@@ skipping 242 matching lines @@
 static skiagm::GM* F4(void*) { return new Strokes5GM; }
 
 static skiagm::GMRegistry R0(F0);
 static skiagm::GMRegistry R1(F1);
 static skiagm::GMRegistry R2(F2);
 static skiagm::GMRegistry R3(F3);
 static skiagm::GMRegistry R4(F4);
 
 DEF_GM( return new ZeroLenStrokesGM; )
 DEF_GM( return new TeenyStrokesGM; )