Add refcnting to SkClipStack on SkCanvas

include/gpu/GrContext.h

Index: include/gpu/GrContext.h
diff --git a/include/gpu/GrContext.h b/include/gpu/GrContext.h
index e47ad15519f34a15b753062ebc9b25a1a6ea4529..cf147502770dc341a8adf8f33d973ae331dc7b99 100644
--- a/include/gpu/GrContext.h
+++ b/include/gpu/GrContext.h
@@ -695,7 +695,7 @@ public:
         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);
@@ -704,7 +704,7 @@ public:
         AutoClip(GrContext* context, const SkRect& newClipRect)
         : fContext(context)
         , fNewClipStack(newClipRect) {
-            fNewClipData.fClipStack = &fNewClipStack;
+            fNewClipData.fClipStack.reset(SkRef(&fNewClipStack));
 
             fOldClip = fContext->getClip();
             fContext->setClip(&fNewClipData);