Fix CodecSubset benches seg faults for kIndex8

bench/subset/SubsetTranslateBench.cpp

Index: bench/subset/SubsetTranslateBench.cpp
diff --git a/bench/subset/SubsetTranslateBench.cpp b/bench/subset/SubsetTranslateBench.cpp
index 620b6f4903b8da291ee0c8eb34809385825fb188..70c4458e4fd83a1e8e696ade097689e287daf171 100644
--- a/bench/subset/SubsetTranslateBench.cpp
+++ b/bench/subset/SubsetTranslateBench.cpp
@@ -68,7 +68,12 @@ void SubsetTranslateBench::onDraw(const int n, SkCanvas* canvas) {
             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) {