Add --zero_init to simulate zero-initialized memory in CodecBench

bench/CodecBench.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 "CodecBench.h"
 #include "CodecBenchPriv.h"
 #include "SkBitmap.h"
 #include "SkCodec.h"
+#include "SkCommandLineFlags.h"
 #include "SkOSFile.h"
 
+// Actually zeroing the memory would throw off timing, so we just lie.
+DEFINE_bool(zero_init, false, "Pretend our destination is zero-intialized, simulating Android?");

[scroggo, 2016/01/08 22:20:29]

Hahaha - we could also add this as another option in our matrix of tests, along
with config etc.

+
 CodecBench::CodecBench(SkString baseName, SkData* encoded, SkColorType colorType,
         SkAlphaType alphaType)
     : fColorType(colorType)
     , fAlphaType(alphaType)
     , fData(SkRef(encoded))
 {
     // Parse filename and the color type to give the benchmark a useful name
     fName.printf("Codec_%s_%s%s", baseName.c_str(), color_type_to_str(colorType),
             alpha_type_to_str(alphaType));
 #ifdef SK_DEBUG
@@ skipping 16 matching lines @@
 
     fInfo = codec->getInfo().makeColorType(fColorType).makeAlphaType(fAlphaType);
 
     fPixelStorage.reset(fInfo.getSafeSize(fInfo.minRowBytes()));
 }
 
 void CodecBench::onDraw(int n, SkCanvas* canvas) {
     SkAutoTDelete<SkCodec> codec;
     SkPMColor colorTable[256];
     int colorCount;
+    SkCodec::Options options;
+    if (FLAGS_zero_init) {
+        options.fZeroInitialized = SkCodec::kYes_ZeroInitialized;
+    }
     for (int i = 0; i < n; i++) {
         colorCount = 256;
         codec.reset(SkCodec::NewFromData(fData));
 #ifdef SK_DEBUG
         const SkCodec::Result result =
 #endif
         codec->getPixels(fInfo, fPixelStorage.get(), fInfo.minRowBytes(),
-                         nullptr, colorTable, &colorCount);
+                         &options, colorTable, &colorCount);
         SkASSERT(result == SkCodec::kSuccess
                  || result == SkCodec::kIncompleteInput);
     }
 }