Overhaul microbenchmark so that it can be pulled in easily by any package

src/platform/minijail/readwrite_microbenchmark.cc

Index: src/platform/minijail/readwrite_microbenchmark.cc
diff --git a/src/platform/microbenchmark/benchmarks/readwrite.cc b/src/platform/minijail/readwrite_microbenchmark.cc
similarity index 97%
rename from src/platform/microbenchmark/benchmarks/readwrite.cc
rename to src/platform/minijail/readwrite_microbenchmark.cc
index 72614ee1eb7cbe49aee4eb9d840944be3c42fc3a..889b97c4716cd74c86a12c8fdc980ce2cf81edba 100644
--- a/src/platform/microbenchmark/benchmarks/readwrite.cc
+++ b/src/platform/minijail/readwrite_microbenchmark.cc
@@ -1,7 +1,6 @@
 // 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.
-// Some portions Copyright (c) 2009 The Chromium Authors.
 //
 // Microbenchmark of basic read/write throughput
 #include "microbenchmark/microbenchmark.h"