break ambiguous angle sorting loop

src/pathops/SkOpContour.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkOpContour_DEFINED
 #define SkOpContour_DEFINED
 
 #include "SkOpSegment.h"
@@ skipping 323 matching lines @@
     }
 
     void setReverse() {
         fReverse = true;
     }
 
     void setXor(bool isXor) {
         fXor = isXor;
     }
 
-    void sortAngles() {
+    bool sortAngles() {
         SkASSERT(fCount > 0);
         SkOpSegment* segment = &fHead;
         do {
-            segment->sortAngles();
+            FAIL_IF(!segment->sortAngles());
         } while ((segment = segment->next()));
+        return true;
     }
 
     const SkPoint& start() const {
         return fHead.pts()[0];
     }
 
     void toPartialBackward(SkPathWriter* path) const {
         const SkOpSegment* segment = fTail;
         do {
             SkAssertResult(segment->addCurveTo(segment->tail(), segment->head(), path));
@@ skipping 62 matching lines @@
             SkASSERT(next);
             prev = next;
         }
         SkASSERT(prev);
         prev->setNext(nullptr);
     }
 
 };
 
 #endif