Add a hook for CPU-optimized sRGB-sRGB srcover.

src/core/SkOpts.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 "SkCpu.h"
 #include "SkHalf.h"
 #include "SkOnce.h"
 #include "SkOpts.h"
 
 #define SK_OPTS_NS sk_default
+#include "SkBlend_opts.h"
 #include "SkBlitMask_opts.h"
 #include "SkBlitRow_opts.h"
 #include "SkBlurImageFilter_opts.h"
 #include "SkColorCubeFilter_opts.h"
 #include "SkMorphologyImageFilter_opts.h"
 #include "SkSwizzler_opts.h"
 #include "SkTextureCompressor_opts.h"
 #include "SkXfermode_opts.h"
 
 namespace SK_OPTS_NS {
@@ skipping 42 matching lines @@
     decltype(RGB_to_BGR1)           RGB_to_BGR1           = sk_default::RGB_to_BGR1;
     decltype(gray_to_RGB1)          gray_to_RGB1          = sk_default::gray_to_RGB1;
     decltype(grayA_to_RGBA)         grayA_to_RGBA         = sk_default::grayA_to_RGBA;
     decltype(grayA_to_rgbA)         grayA_to_rgbA         = sk_default::grayA_to_rgbA;
     decltype(inverted_CMYK_to_RGB1) inverted_CMYK_to_RGB1 = sk_default::inverted_CMYK_to_RGB1;
     decltype(inverted_CMYK_to_BGR1) inverted_CMYK_to_BGR1 = sk_default::inverted_CMYK_to_BGR1;
 
     decltype(half_to_float) half_to_float = sk_default::half_to_float;
     decltype(float_to_half) float_to_half = sk_default::float_to_half;
 
+    decltype(srcover_srgb_srgb) srcover_srgb_srgb = sk_default::srcover_srgb_srgb;
+
     // Each Init_foo() is defined in src/opts/SkOpts_foo.cpp.
     void Init_ssse3();
     void Init_sse41();
     void Init_sse42() {}
     void Init_avx() {}
     void Init_avx2() {}
     void Init_neon();
 
     static void init() {
         // TODO: Chrome's not linking _sse* opts on iOS simulator builds.  Bug or feature?
     #if defined(SK_CPU_X86) && !defined(SK_BUILD_FOR_IOS)
         if (SkCpu::Supports(SkCpu::SSSE3)) { Init_ssse3(); }
         if (SkCpu::Supports(SkCpu::SSE41)) { Init_sse41(); }
         if (SkCpu::Supports(SkCpu::SSE42)) { Init_sse42(); }
         if (SkCpu::Supports(SkCpu::AVX  )) { Init_avx();   }
         if (SkCpu::Supports(SkCpu::AVX2 )) { Init_avx2();  }
 
     #elif defined(SK_CPU_ARM32)         && \
           defined(SK_BUILD_FOR_ANDROID) && \
          !defined(SK_BUILD_FOR_ANDROID_FRAMEWORK)
         if (SkCpu::Supports(SkCpu::NEON)) { Init_neon(); }
     #endif
     }
 
     void Init() {
         static SkOnce once;
         once(init);
     }
 }  // namespace SkOpts