Replace deprecated base::NonThreadSafe in extensions in favor of SequenceChecker.

extensions/browser/value_store/value_store_frontend.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 "extensions/browser/value_store/value_store_frontend.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
@@ skipping 91 matching lines @@
   std::unique_ptr<ValueStore> storage_;
 
   base::FilePath db_path_;
 
   DISALLOW_COPY_AND_ASSIGN(Backend);
 };
 
 ValueStoreFrontend::ValueStoreFrontend(
     const scoped_refptr<ValueStoreFactory>& store_factory,
     BackendType backend_type)
-    : backend_(new Backend(store_factory, backend_type)) {}
+    : backend_(new Backend(store_factory, backend_type)) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+}
 
 ValueStoreFrontend::~ValueStoreFrontend() {
-  DCHECK(CalledOnValidThread());
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
 }
 
 void ValueStoreFrontend::Get(const std::string& key,
                              const ReadCallback& callback) {
-  DCHECK(CalledOnValidThread());
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
       base::Bind(&ValueStoreFrontend::Backend::Get,
                  backend_, key, callback));
 }
 
 void ValueStoreFrontend::Set(const std::string& key,
                              std::unique_ptr<base::Value> value) {
-  DCHECK(CalledOnValidThread());
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
       base::Bind(&ValueStoreFrontend::Backend::Set,
                  backend_, key, base::Passed(&value)));
 }
 
 void ValueStoreFrontend::Remove(const std::string& key) {
-  DCHECK(CalledOnValidThread());
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
       base::Bind(&ValueStoreFrontend::Backend::Remove,
                  backend_, key));
 }