probable fix for asan bot

include/gpu/GrClip.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrClip_DEFINED
 #define GrClip_DEFINED
 
@@ skipping 75 matching lines @@
     bool operator!=(const GrClip& other) const {
         return !(*this == other);
     }
 
     const SkClipStack* clipStack() const {
         SkASSERT(kClipStack_ClipType == fClipType);
         return fClip.fStack;
     }
 
     void setClipStack(const SkClipStack* clipStack, const SkIPoint* origin = NULL) {
+        this->reset();
         if (clipStack->isWideOpen()) {
             fClipType = kWideOpen_ClipType;
             fOrigin.setZero();
         } else {
             fClipType = kClipStack_ClipType;
             fClip.fStack = SkRef(clipStack);
             if (origin) {
                 fOrigin = *origin;
             } else {
                 fOrigin.setZero();
@@ skipping 64 matching lines @@
     union Clip {
         const SkClipStack* fStack;
         SkIRect fIRect;
     } fClip;
 
     SkIPoint fOrigin;
     ClipType fClipType;
 };
 
 #endif