ThreadChecker instead of SequenceChecker in classes that use TLS.

chrome/service/cloud_print/cloud_print_token_store.cc

 // Copyright (c) 2011 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 "chrome/service/cloud_print/cloud_print_token_store.h"
 
 #include "base/lazy_instance.h"
 #include "base/threading/thread_local.h"
 
 namespace cloud_print {
 
 // Keep the global CloudPrintTokenStore in a TLS slot so it is impossible to
 // incorrectly from the wrong thread.
 static base::LazyInstance<
     base::ThreadLocalPointer<CloudPrintTokenStore>>::DestructorAtExit lazy_tls =

[gab, 2017/06/02 18:59:05]

Note: this probably shouldn't use TLS. Given access is sequenced (per the
SequenceChecker). From the API "this is only used with
CloudPrintProxyCoreThread". As such this could be a global variable (no TLS) to
which thread-safe access is enforced by a SequenceChecker.

I'll let OWNERS address this in a follow-up.

     LAZY_INSTANCE_INITIALIZER;
 
+// static
 CloudPrintTokenStore* CloudPrintTokenStore::current() {
   return lazy_tls.Pointer()->Get();
 }
 
 CloudPrintTokenStore::CloudPrintTokenStore() {
   lazy_tls.Pointer()->Set(this);
 }
 
 CloudPrintTokenStore::~CloudPrintTokenStore() {
-  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
   lazy_tls.Pointer()->Set(NULL);
 }
 
 void CloudPrintTokenStore::SetToken(const std::string& token) {
-  DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
   token_ = token;
 }
 
 }  // namespace cloud_print