[Background Sync] Align exposed API with spec

third_party/WebKit/Source/modules/background_sync/SyncManager.idl

 // 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.
 
 enum SyncPermissionState {
   "default",
   "denied",
   "granted"
 };
 
 [
     Exposed=(Window,ServiceWorker),
     GarbageCollected,
     RuntimeEnabled=BackgroundSync,
     TypeChecking=Interface,
 ] interface SyncManager {
-    [CallWith=(ScriptState,ExecutionContext),ImplementedAs=registerFunction] Promise<SyncRegistration> register([RuntimeEnabled=BackgroundSyncV2] optional SyncRegistrationOptions options);
-    [CallWith=ScriptState] Promise<SyncRegistration> getRegistration(DOMString tag);
-    [CallWith=ScriptState] Promise<sequence<SyncRegistration>> getRegistrations();
-    [RuntimeEnabled=BackgroundSyncV2, CallWith=ScriptState] Promise<SyncPermissionState> permissionState();
+    [CallWith=(ScriptState,ExecutionContext),ImplementedAs=registerFunction] Promise<void> register(DOMString tag);

[jkarlin, 2015/11/12 17:29:41]

Can you add MeasureAs=BackgroundSyncRegister? So it looks like..

[MeasureAs=BackgroundSyncRegister,CallWith=(ScriptState,ExecutionContext),ImplementedAs=registerFunction]
Pro
    mise<void> register(DOMString tag);

And also add BackgroundSyncRegister to UseCounter.h

That will give us an idea of sync usage. 

+    [CallWith=ScriptState] Promise<sequence<DOMString>> getTags();
 };