Reland of path ops: fix conic weight and partial coincidence

src/pathops/SkOpCoincidence.cpp

Index: src/pathops/SkOpCoincidence.cpp
diff --git a/src/pathops/SkOpCoincidence.cpp b/src/pathops/SkOpCoincidence.cpp
index a22cfc6deb23307857316cf15a3a9189bbd13b79..9175e858be46be58e1d715859777e09e7d146201 100755
--- a/src/pathops/SkOpCoincidence.cpp
+++ b/src/pathops/SkOpCoincidence.cpp
@@ -205,7 +205,7 @@
     SkASSERT(cs != ce);
     SkOpPtT* os = oppSeg->addMissing(oppTs, coinSeg, allocator);
     SkOpPtT* oe = oppSeg->addMissing(oppTe, coinSeg, allocator);
-    SkASSERT(os != oe);
+//    SkASSERT(os != oe);
     cs->addOpp(os);
     ce->addOpp(oe);
     this->add(cs, ce, os, oe, allocator);