Don't call purgeCache() from within GrResource memebers.

src/gpu/GrRenderTarget.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrRenderTarget.h"
@@ skipping 77 matching lines @@
     if (fResolveRect.isEmpty()) {
         fResolveRect.setLargestInverted();
     } else {
         if (!fResolveRect.intersect(0, 0, this->width(), this->height())) {
             fResolveRect.setLargestInverted();
         }
     }
 }
 
 void GrRenderTarget::setStencilBuffer(GrStencilBuffer* stencilBuffer) {
-    if (stencilBuffer == fStencilBuffer) {
-        return;
-    }
-
-    if (NULL != fStencilBuffer) {
-        fStencilBuffer->unref();
-
-        GrContext* context = this->getContext();
-        if (NULL != context) {
-            context->purgeCache();
-        }
-
-        if (NULL != context) {
-            context->purgeCache();
-        }
-    }
-
-    fStencilBuffer = stencilBuffer;
-
-    if (NULL != fStencilBuffer) {
-        fStencilBuffer->ref();
-    }
+    SkRefCnt_SafeAssign(fStencilBuffer, stencilBuffer);
 }
 
 void GrRenderTarget::onRelease() {
     this->setStencilBuffer(NULL);
 
     INHERITED::onRelease();
 }
 
 void GrRenderTarget::onAbandon() {
     this->setStencilBuffer(NULL);
 
     INHERITED::onAbandon();
 }