Fix CodecSubset benches seg faults for kIndex8

bench/subset/SubsetTranslateBench.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 "SubsetTranslateBench.h"
 #include "SubsetBenchPriv.h"
 #include "SkData.h"
@@ skipping 50 matching lines @@
         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);
 
             SkBitmap bitmap;
             // Note that we use the same bitmap for all of the subsets.
             // It might be larger than necessary for the end subsets.
-            bitmap.allocPixels(info.makeWH(fSubsetWidth, fSubsetHeight));
+            if (kIndex_8_SkColorType == fColorType) {

[scroggo, 2015/06/30 16:40:19]

This code is almost exactly the same. Can we write a common function? (Is there
already a file for common functions for bench decodes?)

[msarett, 2015/06/30 18:40:28]

Yes there is, good idea.

+                bitmap.allocPixels(info.makeWH(fSubsetWidth, fSubsetHeight), NULL,
+                        SkNEW_ARGS(SkColorTable, (colors, colorCount)));
+            } else {
+                bitmap.allocPixels(info.makeWH(fSubsetWidth, fSubsetHeight));
+            }
 
             for (int x = 0; x < info.width(); x += fSubsetWidth) {
                 for (int y = 0; y < info.height(); y += fSubsetHeight) {
                     scanlineDecoder->skipScanlines(y);
                     const uint32_t currSubsetWidth =
                             x + (int) fSubsetWidth > info.width() ?
                             info.width() - x : fSubsetWidth;
                     const uint32_t currSubsetHeight =
                             y + (int) fSubsetHeight > info.height() ?
                             info.height() - y : fSubsetHeight;
@@ skipping 33 matching lines @@
                     const uint32_t currSubsetHeight = y + (int) fSubsetHeight > height ?
                             height - y : fSubsetHeight;
                     SkIRect rect = SkIRect::MakeXYWH(x, y, currSubsetWidth,
                             currSubsetHeight);
                     decoder->decodeSubset(&bitmap, rect, fColorType);
                 }
             }
         }
     }
 }