run iwyu on base!

base/threading/non_thread_safe.cc

 // 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"
+#include "base/threading/thread_checker.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