Enable AA stencil clip for mixed samples

src/gpu/GrPipelineBuilder.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrPipelineBuilder_DEFINED
 #define GrPipelineBuilder_DEFINED
 
@@ skipping 191 matching lines @@
      *
      * @param target  The render target to set.
      */
     void setRenderTarget(GrRenderTarget* target) { fRenderTarget.reset(SkSafeRef(target)); }
 
     /**
      * Returns whether the rasterizer and stencil test (if any) will run at a higher sample rate
      * than the color buffer. In is scenario, the higher sample rate is resolved during blending.
      */
     bool hasMixedSamples() const {
-        return this->isHWAntialias() && !fRenderTarget->isUnifiedMultisampled();
+        return fRenderTarget->hasMixedSamples() &&
+               (this->isHWAntialias() || !fStencilSettings.isDisabled());
     }
 
     /// @}
 
     ///////////////////////////////////////////////////////////////////////////
     /// @name Stencil
     ////
 
     const GrStencilSettings& getStencil() const { return fStencilSettings; }
 
@@ skipping 181 matching lines @@
     FragmentProcessorArray                  fCoverageFragmentProcessors;
     GrClip                                  fClip;
 
     mutable GrProcOptInfo fColorProcInfo;
     mutable GrProcOptInfo fCoverageProcInfo;
 
     friend class GrPipeline;
 };
 
 #endif