Provides multiple implementations of Android's SkBitmapRegionDecoder

src/utils/SkBitmapRegionSampler.h

Index: src/utils/SkBitmapRegionSampler.h
diff --git a/src/utils/SkBitmapRegionSampler.h b/src/utils/SkBitmapRegionSampler.h
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index 0000000000000000000000000000000000000000..c819a677b5c192c690506aae4a3e227dda210367
--- /dev/null
+++ b/src/utils/SkBitmapRegionSampler.h
@@ -0,0 +1,41 @@
+/*
+ * 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 "SkBitmapRegionDecoder.h"
+#include "SkImageDecoder.h"
+#include "SkTemplates.h"
+
+/*
+ * This class aims to duplicate the current implementation of
+ * SkBitmapRegionDecoder in Android.
+ */
+class SkBitmapRegionSampler : public SkBitmapRegionDecoder {
+public:
+
+    /*
+     * Takes ownership of pointer to decoder
+     */
+    SkBitmapRegionSampler(SkImageDecoder* decoder, int width, int height);
+
+    /*
+     * This has several key differences from the Android version:

[scroggo, 2015/09/02 21:32:25]

"several" or three?

[msarett, 2015/09/03 19:20:52]

Acknowledged.

+     *     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 SkBitmapRegionDecoder INHERITED;
+
+};