Simplified stencil buffer caching

https://codereview.appspot.com/6503073/



git-svn-id: http://skia.googlecode.com/svn/trunk@5400 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/gpu/GrRenderTarget.h b/include/gpu/GrRenderTarget.h
index d6e8ee0..f3add50 100644
--- a/include/gpu/GrRenderTarget.h
+++ b/include/gpu/GrRenderTarget.h
@@ -168,6 +168,10 @@
         fTexture = NULL;
     }
 
+    // override of GrResource
+    virtual void onAbandon() SK_OVERRIDE;
+    virtual void onRelease() SK_OVERRIDE;
+
 private:
     GrStencilBuffer*  fStencilBuffer;
     GrTexture*        fTexture; // not ref'ed