[sync] WebContentsObserver based sessions notifications

components/browser_sync/profile_sync_service.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 "components/browser_sync/profile_sync_service.h"
 
 #include <stddef.h>
 
 #include <cstddef>
 #include <map>
@@ skipping 207 matching lines @@
   DCHECK(thread_checker_.CalledOnValidThread());
   sync_client_->Initialize();
 
   // We don't pass StartupController an Unretained reference to future-proof
   // against the controller impl changing to post tasks.
   startup_controller_ = base::MakeUnique<syncer::StartupController>(
       &sync_prefs_,
       base::Bind(&ProfileSyncService::CanEngineStart, base::Unretained(this)),
       base::Bind(&ProfileSyncService::StartUpSlowEngineComponents,
                  weak_factory_.GetWeakPtr()));
-  std::unique_ptr<sync_sessions::LocalSessionEventRouter> router(
-      sync_client_->GetSyncSessionsClient()->GetLocalSessionEventRouter());
+  sync_sessions::LocalSessionEventRouter* router =
+      sync_client_->GetSyncSessionsClient()->GetLocalSessionEventRouter();
   local_device_ = sync_client_->GetSyncApiComponentFactory()
                       ->CreateLocalDeviceInfoProvider();
   sync_stopped_reporter_ = base::MakeUnique<syncer::SyncStoppedReporter>(
       sync_service_url_, local_device_->GetSyncUserAgent(),
       url_request_context_, syncer::SyncStoppedReporter::ResultCallback());
   sessions_sync_manager_ = base::MakeUnique<SessionsSyncManager>(
       sync_client_->GetSyncSessionsClient(), &sync_prefs_, local_device_.get(),
       std::move(router),
       base::Bind(&ProfileSyncService::NotifyForeignSessionUpdated,
                  sync_enabled_weak_factory_.GetWeakPtr()),
@@ skipping 2197 matching lines @@
     return;
 
   DCHECK(startup_controller_->IsSetupInProgress());
   startup_controller_->SetSetupInProgress(false);
 
   if (IsEngineInitialized())
     ReconfigureDatatypeManager();
   NotifyObservers();
 }
 }  // namespace browser_sync