Simple change to add json results writer to kilobench

tools/kilobench/kilobench.cpp

Index: tools/kilobench/kilobench.cpp
diff --git a/tools/kilobench/kilobench.cpp b/tools/kilobench/kilobench.cpp
index 438e582324fb2e8c97f1da061e7d9a3f8760d870..940e3cc213a0b2696de0c5b63a364c4bd7e1c2e6 100644
--- a/tools/kilobench/kilobench.cpp
+++ b/tools/kilobench/kilobench.cpp
@@ -62,6 +62,11 @@ DEFINE_int32(maxLoops, 1000000, "Never run a bench more times than this.");
 DEFINE_int32(loops, kDefaultLoops, loops_help_txt().c_str());
 DEFINE_double(gpuMs, 5, "Target bench time in millseconds for GPU.");
 DEFINE_string2(writePath, w, "", "If set, write bitmaps here as .pngs.");
+DEFINE_string(outResultsFile, "", "If given, write results here as JSON.");
+DEFINE_string(key, "",
+              "Space-separated key/value pairs to add to JSON identifying this builder.");
+DEFINE_string(properties, "",
+              "Space-separated key/value pairs to add to JSON identifying this run.");
 
 namespace kilobench {
 class BenchmarkStream {
@@ -327,7 +332,7 @@ static SkString humanize(double ms) {
 }
 #define HUMANIZE(ms) humanize(ms).c_str()
 
-void benchmark_inner_loop(Benchmark* bench, GrContextFactory* ctxFactory) {
+void benchmark_inner_loop(Benchmark* bench, GrContextFactory* ctxFactory, ResultsWriter* log) {
     SkTArray<double> samples;
     GPUTarget target;
     SkAssertResult(target.init(bench, ctxFactory, false,
@@ -369,16 +374,48 @@ void benchmark_inner_loop(Benchmark* bench, GrContextFactory* ctxFactory) {
         pngFilename.append(".png");
         write_canvas_png(&target, pngFilename);
     }
+
+    log->config("gpu");
+    log->configOption("name", bench->getName());
+    log->metric("min_ms",    stats.min);
+    log->metric("median_ms", stats.median);
 }
 
 } // namespace kilobench
 
+static ResultsWriter* setup_log() {
+    ResultsWriter* log;
+    if (!FLAGS_outResultsFile.isEmpty()) {
+        log = new NanoJSONResultsWriter(FLAGS_outResultsFile[0]);
+    } else {
+        log = new ResultsWriter;
+    }
+
+    if (1 == FLAGS_properties.count() % 2) {
+        SkDebugf("ERROR: --properties must be passed with an even number of arguments.\n");
+        return 1;
+    }
+    for (int i = 1; i < FLAGS_properties.count(); i += 2) {
+        log->property(FLAGS_properties[i-1], FLAGS_properties[i]);
+    }
+
+    if (1 == FLAGS_key.count() % 2) {
+        SkDebugf("ERROR: --key must be passed with an even number of arguments.\n");
+        return 1;
+    }
+    for (int i = 1; i < FLAGS_key.count(); i += 2) {
+        log->key(FLAGS_key[i-1], FLAGS_key[i]);
+    }
+    return log;
+}
 int kilobench_main() {
     SkAutoTDelete<GrContextFactory> ctxFactory;
 
     GrContextOptions grContextOpts;
     ctxFactory.reset(new GrContextFactory(grContextOpts));
 
+    SkAutoTDelete<ResultsWriter> log(setup_log());
+
     kilobench::BenchmarkStream benchStream;
 
     SkDebugf("loops\tmin\tmedian\tmean\tmax\tstddev\t%-*s\tconfig\tbench\n",