[sync] Prevent sessions flare on startup

chrome/browser/sync/sessions/sync_sessions_web_contents_router.h

 // Copyright 2017 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.
 
 #ifndef CHROME_BROWSER_SYNC_SESSIONS_SYNC_SESSIONS_WEB_CONTENTS_ROUTER_H_
 #define CHROME_BROWSER_SYNC_SESSIONS_SYNC_SESSIONS_WEB_CONTENTS_ROUTER_H_
 
 #include "base/callback_list.h"
 
 // Android has no BrowserList or TabStripModel, so we exclude code that refers
 // to those two things. For non-android platforms, this code is used to
 // ensure we are notified of tabs being added and moved between tab strips.
 
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/sync/model/syncable_service.h"
 #include "components/sync_sessions/local_session_event_router.h"
 
 namespace content {
 class WebContents;
 }  // namespace content
 
 class Profile;
 
 namespace sync_sessions {
 
 class BrowserListRouterHelper;
+class SyncSessionsClient;
 
 // WebContentsObserver-based implementation of LocalSessionEventRouter. This
 // class is responsible for notifying Sessions Sync when local tabs are
 // modified. It does this by forwarding the events pushed to it by individual
 // WebContentsObservers, which are scoped to a single WebContents/tab.
 class SyncSessionsWebContentsRouter : public LocalSessionEventRouter,
                                       public KeyedService {
  public:
   explicit SyncSessionsWebContentsRouter(Profile* profile);
 
   // Notify the router that the tab corresponding to |web_contents| has been
   // modified in some way.
   void NotifyTabModified(content::WebContents* web_contents);
   // Inject a flare that can be used to start sync. See the comment for
   // StartSyncFlare in syncable_service.h for more.
   void InjectStartSyncFlare(syncer::SyncableService::StartSyncFlare flare);
+  void SetSyncSessionsClient(SyncSessionsClient* sessions_client) {

[skym, 2017/04/18 15:50:51]

https://google.github.io/styleguide/cppguide.html#Function_Names

I thought the name should be something like set_sync_sessions_client(...), but
apparently that is optional. I personally like your casing more. So lets not
change anything :)

[Patrick Noland, 2017/04/18 22:37:41]

Acknowledged.

+    sessions_client_ = sessions_client;
+  }
 
   // SessionsSyncManager::LocalEventRouter implementation.
   void StartRoutingTo(LocalSessionEventHandler* handler) override;
   void Stop() override;
 
   // KeyedService implementation.
   void Shutdown() override;
 
  protected:
   ~SyncSessionsWebContentsRouter() override;
 
  private:
   void OnFaviconsChanged(const std::set<GURL>& page_urls, const GURL& icon_url);
 
   std::unique_ptr<base::CallbackList<void(const std::set<GURL>&,
                                           const GURL&)>::Subscription>
       favicon_changed_subscription_;
+  SyncSessionsClient* sessions_client_ = nullptr;
   syncer::SyncableService::StartSyncFlare flare_;
   LocalSessionEventHandler* handler_ = nullptr;
 
 #if !defined(OS_ANDROID)
   std::unique_ptr<BrowserListRouterHelper> browser_list_helper_;
 #endif  // !defined(OS_ANDROID)
 
   DISALLOW_COPY_AND_ASSIGN(SyncSessionsWebContentsRouter);
 };
 
 }  // namespace sync_sessions
 
 #endif  // CHROME_BROWSER_SYNC_SESSIONS_SYNC_SESSIONS_WEB_CONTENTS_ROUTER_H_