path ops work in progress

src/pathops/SkOpContour.h

Index: src/pathops/SkOpContour.h
diff --git a/src/pathops/SkOpContour.h b/src/pathops/SkOpContour.h
index a5635fe3d2b59b083dcb5801df931fa71de103ac..a4ec6d398f04bdbab27a11bc0867bbc55be657d3 100644
--- a/src/pathops/SkOpContour.h
+++ b/src/pathops/SkOpContour.h
@@ -36,7 +36,7 @@ public:
                 : fBounds.fTop < rh.fBounds.fTop;
     }
 
-    void addCoincident(int index, SkOpContour* other, int otherIndex,
+    bool addCoincident(int index, SkOpContour* other, int otherIndex,
                        const SkIntersections& ts, bool swap);
     void addCoincidentPoints();
 
@@ -63,7 +63,7 @@ public:
         fSegments[segIndex].addOtherT(tIndex, otherT, otherIndex);
     }
 
-    void addPartialCoincident(int index, SkOpContour* other, int otherIndex,
+    bool addPartialCoincident(int index, SkOpContour* other, int otherIndex,
                        const SkIntersections& ts, int ptIndex, bool swap);
 
     int addQuad(const SkPoint pts[3]) {
@@ -100,6 +100,9 @@ public:
             if (segment->verb() == SkPath::kLine_Verb) {
                 continue;
             }
+            if (segment->done()) {
+                continue;   // likely coincident, nothing to do
+            }
             segment->checkEnds();
         }
     }