Enable stencil clipping in mixed sampled render targets

include/gpu/GrRenderTarget.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrRenderTarget_DEFINED
 #define GrRenderTarget_DEFINED
 
@@ skipping 63 matching lines @@
     }
 
     /**
      * @return the number of stencil samples-per-pixel, or zero if non-MSAA.
      */
     int numStencilSamples() const {
         return fDesc.fSampleCnt;
     }
 
     /**
+     * @return the number of actual raster samples-per-pixel, or zero if non-MSAA.
+     */
+    int numRasterSamples() const {
+        return fStencilAttachment ? this->numStencilSamples() : this->numColorSamples();
+    }
+
+    /**
      * @return true if the surface is mixed sampled, false otherwise.
      */
     bool hasMixedSamples() const {
         SkASSERT(kStencil_SampleConfig != fSampleConfig ||
                  this->isStencilBufferMultisampled());
         return kStencil_SampleConfig == fSampleConfig;
     }
 
     /**
      * Call to indicate the multisample contents were modified such that the
@@ skipping 82 matching lines @@
     GrStencilAttachment*  fStencilAttachment;
     SampleConfig          fSampleConfig;
 
     SkIRect               fResolveRect;
 
     typedef GrSurface INHERITED;
 };
 
 
 #endif