[BackgroundSync] Remove BackgroundSyncRegistrationHandle

content/browser/background_sync/background_sync_registration_handle.cc

-// 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.
-
-#include "content/browser/background_sync/background_sync_registration_handle.h"
-
-#include "content/browser/background_sync/background_sync_manager.h"
-#include "content/public/browser/browser_thread.h"
-
-namespace content {
-
-BackgroundSyncRegistrationHandle::~BackgroundSyncRegistrationHandle() {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  if (IsValid() && background_sync_manager_)
-    background_sync_manager_->ReleaseRegistrationHandle(handle_id_);
-}
-
-bool BackgroundSyncRegistrationHandle::IsValid() const {
-  return registration_ != nullptr;
-}
-
-BackgroundSyncRegistrationHandle::BackgroundSyncRegistrationHandle(
-    base::WeakPtr<BackgroundSyncManager> background_sync_manager,
-    HandleId handle_id)
-    : background_sync_manager_(background_sync_manager),
-      handle_id_(handle_id),
-      registration_(
-          background_sync_manager_->GetRegistrationForHandle(handle_id_)) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  DCHECK(background_sync_manager_);
-}
-
-}  // namespace content