Make nanobench --outResultsFile only work with Release builds.

bench/nanobench.cpp

Index: bench/nanobench.cpp
diff --git a/bench/nanobench.cpp b/bench/nanobench.cpp
index 7efd858c5cd5a8a0e761c399a839fa6964526e2b..1ef1bf6fc3c9f10c6fbfe0152f5996a8bc603e8a 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -1053,9 +1053,11 @@ int nanobench_main() {
     }
 
     SkAutoTDelete<ResultsWriter> log(new ResultsWriter);
+#if defined(SK_RELEASE)

[jcgregorio, 2016/01/20 17:38:28]

Do you also want to emit a warning that the results file isn't being written?

[mtklein, 2016/01/20 17:41:18]

Done.

     if (!FLAGS_outResultsFile.isEmpty()) {
         log.reset(new NanoJSONResultsWriter(FLAGS_outResultsFile[0]));
     }
+#endif
 
     if (1 == FLAGS_properties.count() % 2) {
         SkDebugf("ERROR: --properties must be passed with an even number of arguments.\n");