Add a simple microbenchmark framework, packaging, and sample tests.

src/platform/microbenchmark/SConstruct

+# -*- python -*-
+
+# Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+
+env = Environment()
+
+driver_sources = env.Split("""microbenchmark.cc
+                              main.cc""")
+
+benchmark_sources = env.Split("""benchmarks/getpid.cc
+                                 benchmarks/readwrite.cc""")
+
+env.Append(
+    CPPPATH=['..', '../../third_party/chrome/files', '../../common'],
+    CCFLAGS=['-g', '-fno-exceptions', '-Wall', '-Werror'],
+    LIBPATH=['../../third_party/chrome'],
+    LIBS=['base', 'pthread', 'rt', File('/usr/lib/libgtest.a')],
+)
+
+env_bin = env.Clone()
+env_bin.Program('microbenchmark_runner', driver_sources + benchmark_sources)