[sync] Prevent sessions flare on startup

chrome/browser/sync/chrome_sync_client.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 "chrome/browser/sync/chrome_sync_client.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 174 matching lines @@
   }
 
   sync_sessions::LocalSessionEventRouter* GetLocalSessionEventRouter()
       override {
     syncer::SyncableService::StartSyncFlare flare(
         sync_start_util::GetFlareForSyncableService(profile_->GetPath()));
     sync_sessions::SyncSessionsWebContentsRouter* router =
         sync_sessions::SyncSessionsWebContentsRouterFactory::GetForProfile(
             profile_);
     router->InjectStartSyncFlare(flare);
+    router->SetSyncSessionsClient(this);
     return router;
   }
 
  private:
   Profile* profile_;
   std::unique_ptr<sync_sessions::SyncedWindowDelegatesGetter>
       window_delegates_getter_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncSessionsClientImpl);
 };
@@ skipping 501 matching lines @@
   sync_service->RegisterDataTypeController(
       base::MakeUnique<SupervisedUserSyncDataTypeController>(
           syncer::SUPERVISED_USER_SETTINGS, error_callback, this, profile_));
   sync_service->RegisterDataTypeController(
       base::MakeUnique<SupervisedUserSyncDataTypeController>(
           syncer::SUPERVISED_USER_WHITELISTS, error_callback, this, profile_));
 #endif  // BUILDFLAG(ENABLE_SUPERVISED_USERS)
 }
 
 }  // namespace browser_sync