[Background Sync] Converting Blink code to the MVP API

Source/modules/background_sync/PeriodicSyncManager.idl

Index: Source/modules/background_sync/PeriodicSyncManager.idl
diff --git a/Source/modules/background_sync/PeriodicSyncManager.idl b/Source/modules/background_sync/PeriodicSyncManager.idl
new file mode 100644
index 0000000000000000000000000000000000000000..44c3f76f1afca526b263ca016e018eba55db2380
--- /dev/null
+++ b/Source/modules/background_sync/PeriodicSyncManager.idl
@@ -0,0 +1,16 @@
+// Copyright 2015 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.
+
+[
+    Exposed=(Window,ServiceWorker),
+    GarbageCollected,
+    RuntimeEnabled=BackgroundSync,
+    TypeChecking=Interface,
+] interface PeriodicSyncManager {
+    [CallWith=ScriptState,ImplementedAs=registerFunction] Promise<PeriodicSyncRegistration> register([RuntimeEnabled=BackgroundSyncV2] optional PeriodicSyncRegistrationOptions options);
+    [RuntimeEnabled=BackgroundSyncV2, CallWith=ScriptState] Promise<PeriodicSyncRegistration> getRegistration(DOMString tag);
+    [RuntimeEnabled=BackgroundSyncV2, CallWith=ScriptState] Promise<sequence<PeriodicSyncRegistration>> getRegistrations();
+    [RuntimeEnabled=BackgroundSyncV2, CallWith=ScriptState] Promise<SyncPermissionState> permissionState();
+    [RuntimeEnabled=BackgroundSyncV2] readonly attribute unsigned long minPossiblePeriod;
+};