Reduce overhead for linear color xforms

bench/ColorCodecBench.cpp

Index: bench/ColorCodecBench.cpp
diff --git a/bench/ColorCodecBench.cpp b/bench/ColorCodecBench.cpp
index 9aa5d739780185b3933bdfa404991e8bb554c41f..e35aef87c93bd7c1638de88c59a70a8e829823ee 100644
--- a/bench/ColorCodecBench.cpp
+++ b/bench/ColorCodecBench.cpp
@@ -161,13 +161,14 @@ void ColorCodecBench::onDelayedSetup() {
     }
 
     fSrcInfo = codec->getInfo().makeColorType(kRGBA_8888_SkColorType);
+    fDstInfo = fSrcInfo;
 
     if (FLAGS_half) {
         fDstInfo = fDstInfo.makeColorType(kRGBA_F16_SkColorType);
         fDstSpace = fDstSpace->makeLinearGamma();
     }
 
-    fDstInfo = fSrcInfo.makeColorSpace(fDstSpace);
+    fDstInfo = fDstInfo.makeColorSpace(fDstSpace);
 
     fDst.reset(fDstInfo.getSafeSize(fDstInfo.minRowBytes()));