Create fragment processor for performing input color blend with child processor

src/gpu/gl/GrGLBlend.h

Index: src/gpu/gl/GrGLBlend.h
diff --git a/src/gpu/gl/GrGLBlend.h b/src/gpu/gl/GrGLBlend.h
deleted file mode 100644
index af447b47bf29704276e07b88779d70cecf944b5f..0000000000000000000000000000000000000000
--- a/src/gpu/gl/GrGLBlend.h
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * Copyright 2015 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef GrGLBlend_DEFINED
-#define GrGLBlend_DEFINED
-
-#include "SkXfermode.h"
-
-class GrGLFragmentBuilder;
-
-namespace GrGLBlend {
-    /*
-     * Appends GLSL code to fsBuilder that assigns a specified blend of the srcColor and dstColor
-     * variables to the outColor variable.
-     */
-    void AppendPorterDuffBlend(GrGLFragmentBuilder* fsBuilder, const char* srcColor,
-                               const char* dstColor, const char* outColor, SkXfermode::Mode mode);
-};
-
-#endif