Refactor SkBitmapRegionDecoderInterface for Android

bench/BitmapRegionDecoderBench.cpp

Index: bench/BitmapRegionDecoderBench.cpp
diff --git a/bench/BitmapRegionDecoderBench.cpp b/bench/BitmapRegionDecoderBench.cpp
index 092693619bb8be5796a9de50be373dde4e9eb186..70e3e760e0c036145baf85d3a9193fc0bdf84ddd 100644
--- a/bench/BitmapRegionDecoderBench.cpp
+++ b/bench/BitmapRegionDecoderBench.cpp
@@ -61,10 +61,8 @@ void BitmapRegionDecoderBench::onDelayedSetup() {
 }
 
 void BitmapRegionDecoderBench::onDraw(int n, SkCanvas* canvas) {
-    SkAutoTDelete<SkBitmap> bitmap;
     for (int i = 0; i < n; i++) {
-        bitmap.reset(fBRD->decodeRegion(fSubset.left(), fSubset.top(), fSubset.width(),
-                fSubset.height(), fSampleSize, fColorType));
-        SkASSERT(nullptr != bitmap.get());
+        SkBitmap bm;
+        SkAssertResult(fBRD->decodeRegion(&bm, nullptr, fSubset, fSampleSize, fColorType, false));
     }
 }