Rename SkBitmapRegionDecoder and Create function

tools/SkBitmapRegionSampler.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 "SkBitmap.h"
-#include "SkBitmapRegionDecoderInterface.h"
+#include "SkBitmapRegionDecoder.h"
 #include "SkImageDecoder.h"
 #include "SkTemplates.h"
 
 /*
  * This class aims to duplicate the current implementation of
  * SkBitmapRegionDecoder in Android.
  */
-class SkBitmapRegionSampler : public SkBitmapRegionDecoderInterface {
+class SkBitmapRegionSampler : public SkBitmapRegionDecoder {
 public:
 
     /*
      * Takes ownership of pointer to decoder
      */
     SkBitmapRegionSampler(SkImageDecoder* decoder, int width, int height);
 
     bool decodeRegion(SkBitmap* bitmap, SkBitmap::Allocator* allocator,
                       const SkIRect& desiredSubset, int sampleSize,
                       SkColorType colorType, bool requireUnpremul) override;
 
     bool conversionSupported(SkColorType colorType) override {
         // SkBitmapRegionSampler does not allow the client to check if the conversion
         // is supported.  We will return true as a default.  If the conversion is in
         // fact not supported, decodeRegion() will ignore the prefColorType and choose
         // its own color type.  We catch this and fail non-fatally in our test code.
         return true;
     }
 
     SkEncodedFormat getEncodedFormat() override { return (SkEncodedFormat) fDecoder->getFormat(); }
 
 private:
 
     SkAutoTDelete<SkImageDecoder> fDecoder;
 
-    typedef SkBitmapRegionDecoderInterface INHERITED;
+    typedef SkBitmapRegionDecoder INHERITED;
 
 };