Provides multiple implementations of Android's SkBitmapRegionDecoder

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 "SkImageDecoder.h"
+#include "SkTemplates.h"
+
+/*
+ * This class aims to duplicate the current implementation of
+ * SkBitmapRegionDecoder in Android.
+ */
+class SkBitmapRegionSampler : public SkBitmapRegionDecoderInterface {
+public:
+
+    /*
+     * Takes ownership of pointer to decoder
+     */
+    SkBitmapRegionSampler(SkImageDecoder* decoder, int width, int height);
+
+    /*
+     * Three differences from the Android version:
+     *     Returns a Skia bitmap instead of an Android bitmap.
+     *     Android version attempts to reuse a recycled bitmap.
+     *     Removed the options object and used parameters for color type and
+     *     sample size.
+     */
+    SkBitmap* decodeRegion(int start_x, int start_y, int width, int height,
+                           int sampleSize, SkColorType prefColorType) override;
+
+private:
+
+    SkAutoTDelete<SkImageDecoder> fDecoder;
+
+    typedef SkBitmapRegionDecoderInterface INHERITED;
+
+};