NEON optimizations for gray -> RGBA (or BGRA) conversions

bench/SwizzleBench.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Benchmark.h"
 #include "SkOpts.h"
 
@@ skipping 14 matching lines @@
     const char* fName;
     SkOpts::Swizzle_8888 fFn;
 };
 
 
 DEF_BENCH(return new SwizzleBench("SkOpts::RGBA_to_rgbA", SkOpts::RGBA_to_rgbA));
 DEF_BENCH(return new SwizzleBench("SkOpts::RGBA_to_bgrA", SkOpts::RGBA_to_bgrA));
 DEF_BENCH(return new SwizzleBench("SkOpts::RGBA_to_BGRA", SkOpts::RGBA_to_BGRA));
 DEF_BENCH(return new SwizzleBench("SkOpts::RGB_to_RGB1",  SkOpts::RGB_to_RGB1));
 DEF_BENCH(return new SwizzleBench("SkOpts::RGB_to_BGR1",  SkOpts::RGB_to_BGR1));
+DEF_BENCH(return new SwizzleBench("SkOpts::gray_to_RGB1", SkOpts::gray_to_RGB1));