Add refcnting to SkClipStack on SkCanvas

include/gpu/GrContext.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 GrContext_DEFINED
 #define GrContext_DEFINED
 
@@ skipping 677 matching lines @@
         // This enum exists to require a caller of the constructor to acknowledge that the clip will
         // initially be wide open. It also could be extended if there are other desirable initial
         // clip states.
         enum InitialClip {
             kWideOpen_InitialClip,
         };
 
         AutoClip(GrContext* context, InitialClip SkDEBUGCODE(initialState))
         : fContext(context) {
             SkASSERT(kWideOpen_InitialClip == initialState);
-            fNewClipData.fClipStack = &fNewClipStack;
+            fNewClipData.fClipStack.reset(SkRef(&fNewClipStack));
 
             fOldClip = context->getClip();
             context->setClip(&fNewClipData);
         }
 
         AutoClip(GrContext* context, const SkRect& newClipRect)
         : fContext(context)
         , fNewClipStack(newClipRect) {
-            fNewClipData.fClipStack = &fNewClipStack;
+            fNewClipData.fClipStack.reset(SkRef(&fNewClipStack));
 
             fOldClip = fContext->getClip();
             fContext->setClip(&fNewClipData);
         }
 
         ~AutoClip() {
             if (fContext) {
                 fContext->setClip(fOldClip);
             }
         }
@@ skipping 132 matching lines @@
     /**
      *  This callback allows the resource cache to callback into the GrContext
      *  when the cache is still over budget after a purge.
      */
     static void OverBudgetCB(void* data);
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif