Allow creating multiple scanline decoders.

bench/subset/SubsetSingleBench.cpp

 /*
  * 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 "SubsetSingleBench.h"
 #include "SubsetBenchPriv.h"
 #include "SkData.h"
@@ skipping 49 matching lines @@
 void SubsetSingleBench::onDraw(const int n, SkCanvas* canvas) {
     // When the color type is kIndex8, we will need to store the color table.  If it is
     // used, it will be initialized by the codec.
     int colorCount;
     SkPMColor colors[256];
     if (fUseCodec) {
         for (int count = 0; count < n; count++) {
             SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(fStream->duplicate()));
             const SkImageInfo info = codec->getInfo().makeColorType(fColorType);
             SkAutoTDeleteArray<uint8_t> row(SkNEW_ARRAY(uint8_t, info.minRowBytes()));
-            SkScanlineDecoder* scanlineDecoder = codec->getScanlineDecoder(
-                    info, NULL, colors, &colorCount);
+            SkAutoTDelete<SkScanlineDecoder> scanlineDecoder(codec->getScanlineDecoder(
+                    info, NULL, colors, &colorCount));
 
             SkBitmap bitmap;
             SkImageInfo subsetInfo = info.makeWH(fSubsetWidth, fSubsetHeight);
             alloc_pixels(&bitmap, subsetInfo, colors, colorCount);
 
             scanlineDecoder->skipScanlines(fOffsetTop);
             uint32_t bpp = info.bytesPerPixel();
             for (uint32_t y = 0; y < fSubsetHeight; y++) {
                 scanlineDecoder->getScanlines(row.get(), 1, 0);
                 memcpy(bitmap.getAddr(0, y), row.get() + fOffsetLeft * bpp,
                         fSubsetWidth * bpp);
             }
         }
     } else {
         for (int count = 0; count < n; count++) {
             SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(fStream));
             int width, height;
             decoder->buildTileIndex(fStream->duplicate(), &width, &height);
             SkBitmap bitmap;
             SkIRect rect = SkIRect::MakeXYWH(fOffsetLeft, fOffsetTop, fSubsetWidth,
                     fSubsetHeight);
             decoder->decodeSubset(&bitmap, rect, fColorType);
         }
     }
 }