fix path ops fuzz bug

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 251 matching lines @@
             }
             segment = segment->next();
         } while (segment);
         return result;
     }
 
     bool moveMultiples() {
         SkASSERT(fCount > 0);
         SkOpSegment* segment = &fHead;
         do {
-            segment->moveMultiples();
+            if (!segment->moveMultiples()) {
+                return false;
+            }
         } while ((segment = segment->next()));
         return true;
     }
 
     void moveNearby() {
         SkASSERT(fCount > 0);
         SkOpSegment* segment = &fHead;
         do {
             segment->moveNearby();
         } while ((segment = segment->next()));
@@ skipping 144 matching lines @@
     bool fXor;  // set if original path had even-odd fill
     bool fOppXor;  // set if opposite path had even-odd fill
     SkDEBUGCODE(int fID);
     SkDEBUGCODE(mutable int fDebugIndent);
 };
 
 class SkOpContourHead : public SkOpContour {
 };
 
 #endif