Make all GrFragmentProcessors GL independent.

src/gpu/glsl/GrGLSLBlend.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "GrGLSLBlend.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 
 //////////////////////////////////////////////////////////////////////////////
@@ skipping 415 matching lines @@
                                                 false);
         // append dst blend
         if(!append_porterduff_term(fsBuilder, dstCoeff, dstColor, srcColor, dstColor, didAppend)) {
             fsBuilder->codeAppend("vec4(0, 0, 0, 0)");
         }
         fsBuilder->codeAppend(";");
     } else {
         emit_advanced_xfermode_code(fsBuilder, srcColor, dstColor, outColor, mode);
     }
 }