Swizzle shader output and blend when using GL_RED to implement kAlpha_8_GrPixelConfig

src/gpu/gl/builders/GrGLProgramBuilder.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 GrGLProgramBuilder_DEFINED
 #define GrGLProgramBuilder_DEFINED
 
@@ skipping 74 matching lines @@
                             int index,
                             const char* outColor,
                             const char* inColor);
     void emitAndInstallProc(const GrPrimitiveProcessor&,
                             const char* outColor,
                             const char* outCoverage);
     void emitAndInstallXferProc(const GrXferProcessor&,
                                 const GrGLSLExpr4& colorIn,
                                 const GrGLSLExpr4& coverageIn,
                                 bool ignoresCoverage);
+    void emitFSOutputSwizzle(bool hasSecondaryOutput);
 
     void verify(const GrPrimitiveProcessor&);
     void verify(const GrXferProcessor&);
     void verify(const GrFragmentProcessor&);
     template <class Proc>
     void emitSamplers(const GrProcessor&,
                       GrGLSLTextureSampler::TextureSamplerArray* outSamplers,
                       GrGLInstalledProc<Proc>*);
 
     bool compileAndAttachShaders(GrGLSLShaderBuilder& shader,
@@ skipping 45 matching lines @@
     GrGLSLPrimitiveProcessor::TransformsOut fOutCoords;
     typedef GrGLSLUniformHandler::UniformHandle UniformHandle;
     SkTArray<UniformHandle> fSamplerUniforms;
 
     GrGLVaryingHandler        fVaryingHandler;
     GrGLUniformHandler        fUniformHandler;
 
     typedef GrGLSLProgramBuilder INHERITED; 
 };
 #endif