Create helper functions to use in computeInvariantOutput calls

src/gpu/GrAARectRenderer.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 "GrAARectRenderer.h"
 #include "GrGpu.h"
 #include "gl/builders/GrGLProgramBuilder.h"
@@ skipping 90 matching lines @@
         : fInRect(this->addVertexAttrib(GrShaderVar("inRect",
                                                     kVec4f_GrSLType,
                                                     GrShaderVar::kAttribute_TypeModifier))) {
     }
 
     const GrShaderVar& fInRect;
 
     virtual bool onIsEqual(const GrProcessor&) const SK_OVERRIDE { return true; }
 
     virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE {
-        inout->fValidFlags = 0;
-        inout->fIsSingleComponent = false;
+        inout->mulByUnknownAlpha();
     }
 
     GR_DECLARE_GEOMETRY_PROCESSOR_TEST;
 
     typedef GrGeometryProcessor INHERITED;
 };
 
 
 GR_DEFINE_GEOMETRY_PROCESSOR_TEST(GrAlignedRectEffect);
 
@@ skipping 123 matching lines @@
         , fInWidthHeight(this->addVertexAttrib(
                 GrShaderVar("inWidthHeight",
                             kVec2f_GrSLType,
                             GrShaderVar::kAttribute_TypeModifier))) {
         this->setWillReadFragmentPosition();
     }
 
     virtual bool onIsEqual(const GrProcessor&) const SK_OVERRIDE { return true; }
 
     virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE {
-        inout->fValidFlags = 0;
-        inout->fIsSingleComponent = false;
+        inout->mulByUnknownAlpha();
     }
 
     const GrShaderVar& fInRectEdge;
     const GrShaderVar& fInWidthHeight;
 
     GR_DECLARE_GEOMETRY_PROCESSOR_TEST;
 
     typedef GrGeometryProcessor INHERITED;
 };
 
@@ skipping 695 matching lines @@
     // can't call mapRect for devInside since it calls sort
     combinedMatrix.mapPoints((SkPoint*)&devInside, (const SkPoint*)&rects[1], 2);
 
     if (devInside.isEmpty()) {
         this->fillAARect(gpu, target, devOutside, SkMatrix::I(), devOutside);
         return;
     }
 
     this->geometryStrokeAARect(gpu, target, devOutside, devOutsideAssist, devInside, true);
 }