Convert child FPs from refs to pending executions when parent converts

include/gpu/GrXferProcessor.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrXferProcessor_DEFINED
 #define GrXferProcessor_DEFINED
 
@@ skipping 225 matching lines @@
             return false;
         }
         return this->onIsEqual(that);
     }
    
 protected:
     GrXferProcessor();
     GrXferProcessor(const DstTexture*, bool willReadDstColor, bool hasMixedSamples);
 
 private:
+    void notifyRefCntIsZero() const final {}
+
     virtual OptFlags onGetOptimizations(const GrProcOptInfo& colorPOI,
                                         const GrProcOptInfo& coveragePOI,
                                         bool doesStencilWrite,
                                         GrColor* overrideColor,
                                         const GrCaps& caps) = 0;
 
     /**
      * Sets a unique key on the GrProcessorKeyBuilder that is directly associated with this xfer
      * processor's GL backend implementation.
      */
@@ skipping 142 matching lines @@
     enum {
         kIllegalXPFClassID = 0,
     };
     static int32_t gCurrXPFClassID;
 
     typedef GrProgramElement INHERITED;
 };
 
 #endif