Swizzle shader output and blend when using GL_RED to implement kAlpha_8_GrPixelConfig

src/gpu/gl/GrGLProgramDesc.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLProgramDesc_DEFINED
 #define GrGLProgramDesc_DEFINED
 
@@ skipping 34 matching lines @@
 
     /**
      * Builds a GL specific program descriptor
      *
      * @param GrPrimitiveProcessor The geometry
      * @param GrPipeline  The optimized drawstate.  The descriptor will represent a program
      *                        which this optstate can use to draw with.  The optstate contains
      *                        general draw information, as well as the specific color, geometry,
      *                        and coverage stages which will be used to generate the GL Program for
      *                        this optstate.
-     * @param GrGLGpu  A GL Gpu, the caps and Gpu object are used to output processor specific
-     *                 parts of the descriptor.
+     * @param GrGLSLCaps     Capabilities of the GLSL backend.
      * @param GrProgramDesc  The built and finalized descriptor
      **/
     static bool Build(GrProgramDesc*,
                       const GrPrimitiveProcessor&,
                       const GrPipeline&,
-                      const GrGLGpu*);
+                      const GrGLSLCaps&);
 };
 
 #endif