Create helper functions to use in computeInvariantOutput calls

src/gpu/GrAAConvexPathRenderer.cpp

 
 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrAAConvexPathRenderer.h"
 
@@ skipping 571 matching lines @@
         : fInQuadEdge(this->addVertexAttrib(GrShaderVar("inQuadEdge",
                                                         kVec4f_GrSLType,
                                                         GrShaderVar::kAttribute_TypeModifier))) {
     }
 
     virtual bool onIsEqual(const GrProcessor& other) const SK_OVERRIDE {
         return true;
     }
 
     virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE {
-        inout->fValidFlags = 0;
-        inout->fIsSingleComponent = false;
+        inout->mulByUnknownAlpha();
     }
 
     const GrShaderVar& fInQuadEdge;
 
     GR_DECLARE_GEOMETRY_PROCESSOR_TEST;
 
     typedef GrFragmentProcessor INHERITED;
 };
 
 GR_DEFINE_GEOMETRY_PROCESSOR_TEST(QuadEdgeEffect);
@@ skipping 109 matching lines @@
                             vOffset,  // start vertex
                             0,        // start index
                             draw.fVertexCnt,
                             draw.fIndexCnt,
                             &devBounds);
         vOffset += draw.fVertexCnt;
     }
 
     return true;
 }