Port SkTextureCompression opts to SkOpts

src/core/SkOpts.h

 /*
  * 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 SkOpts_DEFINED
 #define SkOpts_DEFINED
 
+#include "SkTextureCompressor.h"
 #include "SkTypes.h"
 #include "SkXfermode.h"
 
 struct ProcCoeff;
 
 namespace SkOpts {
     // Call to replace pointers to portable functions with pointers to CPU-specific functions.
     // Thread-safe and idempotent.
     // Called by SkGraphics::Init(), and automatically #if SK_ALLOW_STATIC_GLOBAL_INITIALIZERS.
     void Init();
 
     // Declare function pointers here...
 
     // Returns a fast approximation of 1.0f/sqrtf(x).
     extern float (*rsqrt)(float);
 
     // See SkUtils.h
     extern void (*memset16)(uint16_t[], uint16_t, int);
     extern void (*memset32)(uint32_t[], uint32_t, int);
 
     // May return nullptr if we haven't specialized the given Mode.
     extern SkXfermode* (*create_xfermode)(const ProcCoeff&, SkXfermode::Mode);
 
     typedef void (*BoxBlur)(const SkPMColor*, int, SkPMColor*, int, int, int, int, int);
     extern BoxBlur box_blur_xx, box_blur_xy, box_blur_yx;
 
     typedef void (*Morph)(const SkPMColor*, SkPMColor*, int, int, int, int, int);
     extern Morph dilate_x, dilate_y, erode_x, erode_y;
+
+    typedef bool (*TextureCompressor)(uint8_t* dst, const uint8_t* src,
+                                      int width, int height, size_t rowBytes);
+    extern TextureCompressor (*texture_compressor)(SkColorType, SkTextureCompressor::Format);
+    extern bool (*fill_block_dimensions)(SkTextureCompressor::Format, int* x, int* y);
+
 }
 
 #endif//SkOpts_DEFINED