Pref service: integrate PersistentPrefStoreImpl with PrefStoreManagerImpl.

services/preferences/persistent_pref_store_factory.cc

Index: services/preferences/persistent_pref_store_factory.cc
diff --git a/services/preferences/persistent_pref_store_factory.cc b/services/preferences/persistent_pref_store_factory.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c9909fbbe6942d6d2a07d05e7f0d1a192e63c21c
--- /dev/null
+++ b/services/preferences/persistent_pref_store_factory.cc
@@ -0,0 +1,41 @@
+// Copyright 2017 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 "services/preferences/persistent_pref_store_factory.h"
+
+#include <memory>
+#include <utility>
+
+#include "components/prefs/json_pref_store.h"
+#include "components/prefs/pref_filter.h"
+#include "services/preferences/persistent_pref_store_impl.h"
+
+namespace prefs {
+namespace {
+
+std::unique_ptr<PersistentPrefStoreImpl> CreateSimplePersistentPrefStore(
+    mojom::SimplePersistentPrefStoreConfigurationPtr config,
+    base::SequencedWorkerPool* worker_pool) {
+  return base::MakeUnique<PersistentPrefStoreImpl>(
+      new JsonPrefStore(config->pref_filename,
+                        JsonPrefStore::GetTaskRunnerForFile(
+                            config->pref_filename.DirName(), worker_pool),
+                        nullptr),
+      nullptr);
+}
+
+}  // namespace
+
+std::unique_ptr<PersistentPrefStoreImpl> CreatePersistentPrefStore(
+    mojom::PersistentPrefStoreConfigurationPtr configuration,
+    base::SequencedWorkerPool* worker_pool) {
+  if (configuration->is_simple_configuration()) {
+    return CreateSimplePersistentPrefStore(
+        std::move(configuration->get_simple_configuration()), worker_pool);
+  }
+  NOTREACHED();
+  return nullptr;
+}
+
+}  // namespace prefs