Add performance test skeleton.

test/perf-tests/infra-test.cc

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "testing/gtest-support.h"
+
+namespace v8 {
+namespace infra {
+
+TEST(InfraTest, Constant) {
+  printf("Trace(Constant), Result(10.0), StdDev(1.0)\n");

[Michael Achenbach, 2014/08/24 20:37:57]

I think it might be useful to have one level of hierarchy more here and return:
Graph(Infra), Trace(Constant), Result(10.0), StdDev(1.0)

And teach the benchmark driver to group these graphs and traces.

[Benedikt Meurer, 2014/08/25 04:16:26]

How about using the same output format as Chrome (as found in
testing/perf/perf_test.cc)?

<*>RESULT <graph_name>: <trace_name>= <value> <units>
<*>RESULT <graph_name>: <trace_name>= {<mean>, <std deviation>} <units>
<*>RESULT <graph_name>: <trace_name>= [<value>,value,value,...,] <units>

+}
+
+}  // namespace infra
+}  // namespace v8