Mojo: more idiomatic C++ bindings

mojo/public/cpp/environment/lib/buffer_tls.cc

-// Copyright 2014 The Chromium 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 "mojo/public/cpp/environment/buffer_tls.h"
-
-#include <assert.h>
-
-#include "mojo/public/cpp/environment/lib/buffer_tls_setup.h"
-#include "mojo/public/cpp/utility/lib/thread_local.h"
-
-namespace mojo {
-namespace internal {
-
-static ThreadLocalPointer<Buffer> current_buffer;
-
-void SetUpCurrentBuffer() {
-  current_buffer.Allocate();
-}
-
-void TearDownCurrentBuffer() {
-  assert(!current_buffer.Get());
-  current_buffer.Free();
-}
-
-Buffer* GetCurrentBuffer() {
-  return current_buffer.Get();
-}
-
-Buffer* SetCurrentBuffer(Buffer* buf) {
-  Buffer* old_buf = current_buffer.Get();
-  current_buffer.Set(buf);
-  return old_buf;
-}
-
-}  // namespace internal
-}  // namespace mojo