Migrate Extensions code to Task Scheduler API

chrome/browser/extensions/api/storage/policy_value_store.cc

 // Copyright (c) 2012 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/browser/extensions/api/storage/policy_value_store.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/values.h"
 #include "components/policy/core/common/policy_map.h"
 #include "components/policy/core/common/policy_types.h"
-#include "content/public/browser/browser_thread.h"
+#include "extensions/browser/api/storage/backend_task_runner.h"
 #include "extensions/browser/api/storage/settings_namespace.h"
 #include "extensions/browser/value_store/value_store_change.h"
 
-using content::BrowserThread;
-
 namespace extensions {
 
 namespace {
 
 ValueStore::Status ReadOnlyError() {
   return ValueStore::Status(ValueStore::READ_ONLY,
                             "This is a read-only store.");
 }
 
 }  // namespace
 
 PolicyValueStore::PolicyValueStore(
     const std::string& extension_id,
     const scoped_refptr<SettingsObserverList>& observers,
     std::unique_ptr<ValueStore> delegate)
     : extension_id_(extension_id),
       observers_(observers),
       delegate_(std::move(delegate)) {}
 
 PolicyValueStore::~PolicyValueStore() {}
 
 void PolicyValueStore::SetCurrentPolicy(const policy::PolicyMap& policy) {
-  DCHECK_CURRENTLY_ON(BrowserThread::FILE);
+  DCHECK(IsOnBackendSequence());
   // Convert |policy| to a dictionary value. Only include mandatory policies
   // for now.
   base::DictionaryValue current_policy;
   for (policy::PolicyMap::const_iterator it = policy.begin();
        it != policy.end(); ++it) {
     if (it->second.level == policy::POLICY_LEVEL_MANDATORY) {
       current_policy.SetWithoutPathExpansion(
           it->first, it->second.value->CreateDeepCopy());
     }
   }
@@ skipping 101 matching lines @@
 ValueStore::WriteResult PolicyValueStore::Remove(
     const std::vector<std::string>& keys) {
   return MakeWriteResult(ReadOnlyError());
 }
 
 ValueStore::WriteResult PolicyValueStore::Clear() {
   return MakeWriteResult(ReadOnlyError());
 }
 
 }  // namespace extensions