Move all knowledge of X sampling into SkScaledCodec

src/codec/SkBmpStandardCodec.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.
  */
 
 #include "SkBmpCodec.h"
 #include "SkColorTable.h"
 #include "SkImageInfo.h"
@@ skipping 36 matching lines @@
                        int*) override;
 
     bool onInIco() const override {
         return fInIco;
     }
 
     SkCodec::Result prepareToDecode(const SkImageInfo& dstInfo,
             const SkCodec::Options& options, SkPMColor inputColorPtr[],
             int* inputColorCount) override;
 
+    SkSampler* getSampler() override { return fSwizzler; }
+
 private:
 
     /*
      * Creates the color table
      * Sets colorCount to the new color count if it is non-nullptr
      */
     bool createColorTable(SkAlphaType alphaType, int* colorCount);
 
     bool initializeSwizzler(const SkImageInfo& dstInfo, const Options& opts);
 
     Result decodeRows(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes,
                       const Options& opts) override;
 
     Result decodeIcoMask(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes);
 
     SkAutoTUnref<SkColorTable>          fColorTable;     // owned
     const uint32_t                      fNumColors;
     const uint32_t                      fBytesPerColor;
     const uint32_t                      fOffset;
     SkAutoTDelete<SkSwizzler>           fSwizzler;
     const size_t                        fSrcRowBytes;
     SkAutoTDeleteArray<uint8_t>         fSrcBuffer;
     const bool                          fInIco;
 
     typedef SkBmpCodec INHERITED;
 };