Refactor bitmap scaler to make it easier to migrate rest of chrome to use it

src/core/SkBitmapScaler.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkBitmapScaler_DEFINED
 #define SkBitmapScaler_DEFINED
 
@@ skipping 65 matching lines @@
         RESIZE_FIRST_QUALITY_METHOD = RESIZE_GOOD,
         RESIZE_LAST_QUALITY_METHOD = RESIZE_BEST,
         RESIZE_FIRST_ALGORITHM_METHOD = RESIZE_BOX,
         RESIZE_LAST_ALGORITHM_METHOD = RESIZE_MITCHELL,
     };
 
     static bool Resize(SkBitmap* result,
                        const SkBitmap& source,
                        ResizeMethod method,
                        float dest_width, float dest_height,
-                       const SkConvolutionProcs&,
                        SkBitmap::Allocator* allocator = NULL);
+
+     /** Platforms can also optionally overwrite the convolution functions
+        if we have SIMD versions of them.
+      */
+
+    static void PlatformConvolutionProcs(SkConvolutionProcs*);
 };
 
 #endif