Do not crash nanobench in debug mode

bench/nanobench.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <ctype.h>
 
 #include "nanobench.h"
@@ skipping 621 matching lines @@
                 fCurrentSKP++;
             }
             fCurrentSKP = 0;
             fCurrentScale++;
         }
 
         for (; fCurrentCodec < fImages.count(); fCurrentCodec++) {
             const SkString& path = fImages[fCurrentCodec];
             SkAutoTUnref<SkData> encoded(SkData::NewFromFileName(path.c_str()));
             SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(encoded));
-            SkASSERT(codec);
             if (!codec) {
                 // Nothing to time.
+                SkDebugf("Cannot find codec for %s\n", path.c_str());

[scroggo, 2015/04/24 18:27:24]

I thought you said it printed this without adding this printf? (I've been
running release without your CL and I see a comment like this.) Do we need both?

                 continue;
             }
 
             while (fCurrentColorType < fColorTypes.count()) {
                 const SkColorType colorType = fColorTypes[fCurrentColorType];
                 fCurrentColorType++;
 
                 // Make sure we can decode to this color type.
                 SkImageInfo info = codec->getInfo().makeColorType(colorType);
                 SkAlphaType alphaType;
@@ skipping 337 matching lines @@
 
     return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return nanobench_main();
 }
 #endif