fix path op conic bugs

src/pathops/SkOpContour.h

Index: src/pathops/SkOpContour.h
diff --git a/src/pathops/SkOpContour.h b/src/pathops/SkOpContour.h
index c6120089bded3b7fcba2fdc15aa462013af67d94..d0e09a3a7045cbea343b412e959b791f57720f6a 100644
--- a/src/pathops/SkOpContour.h
+++ b/src/pathops/SkOpContour.h
@@ -397,14 +397,14 @@ public:
     void toPartialBackward(SkPathWriter* path) const {
         const SkOpSegment* segment = fTail;
         do {
-            segment->addCurveTo(segment->tail(), segment->head(), path, true);
+            SkAssertResult(segment->addCurveTo(segment->tail(), segment->head(), path));
         } while ((segment = segment->prev()));
     }
 
     void toPartialForward(SkPathWriter* path) const {
         const SkOpSegment* segment = &fHead;
         do {
-            segment->addCurveTo(segment->head(), segment->tail(), path, true);
+            SkAssertResult(segment->addCurveTo(segment->head(), segment->tail(), path));
         } while ((segment = segment->next()));
     }