Modify ThreadChecker and NonThreadSafe so that their functionality is

base/threading/non_thread_safe.cc

Index: base/threading/non_thread_safe.cc
diff --git a/base/threading/non_thread_safe.cc b/base/threading/non_thread_safe.cc
deleted file mode 100644
index 8b41bc0b4b5569f6af03e6988c6dd0e30045edcd..0000000000000000000000000000000000000000
--- a/base/threading/non_thread_safe.cc
+++ /dev/null
@@ -1,28 +0,0 @@
-// Copyright (c) 2010 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 "base/threading/non_thread_safe.h"
-
-// These checks are only done in debug builds.
-#ifndef NDEBUG
-
-#include "base/logging.h"
-
-namespace base {
-
-NonThreadSafe::~NonThreadSafe() {
-  DCHECK(CalledOnValidThread());
-}
-
-bool NonThreadSafe::CalledOnValidThread() const {
-  return thread_checker_.CalledOnValidThread();
-}
-
-void NonThreadSafe::DetachFromThread() {
-  thread_checker_.DetachFromThread();
-}
-
-}  // namespace base
-
-#endif  // NDEBUG