Allow creating multiple scanline decoders.

bench/subset/SubsetZoomBench.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 "SubsetZoomBench.h"
 #include "SubsetBenchPriv.h"
 #include "SkData.h"
@@ skipping 45 matching lines @@
 void SubsetZoomBench::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));
 
             const int centerX = info.width() / 2;
             const int centerY = info.height() / 2;
             int w = fSubsetWidth;
             int h = fSubsetHeight;
             do {
                 const int subsetStartX = SkTMax(0, centerX - w / 2);
                 const int subsetStartY = SkTMax(0, centerY - h / 2);
                 const int subsetWidth = SkTMin(w, info.width() - subsetStartX);
                 const int subsetHeight = SkTMin(h, info.height() - subsetStartY);
@@ skipping 32 matching lines @@
                 SkBitmap bitmap;
                 SkIRect rect = SkIRect::MakeXYWH(subsetStartX, subsetStartY, subsetWidth,
                         subsetHeight);
                 decoder->decodeSubset(&bitmap, rect, fColorType);
                 w <<= 1;
                 h <<= 1;
             } while (w < 2 * width || h < 2 * height);
         }
     }
 }