[sync] Scope BrowserListRouterHelper to browsers with a matching profile

chrome/browser/sync/sessions/browser_list_router_helper.h

Index: chrome/browser/sync/sessions/browser_list_router_helper.h
diff --git a/chrome/browser/sync/sessions/browser_list_router_helper.h b/chrome/browser/sync/sessions/browser_list_router_helper.h
index 16eccdd90161bf2694b6c7adf7a985344602e202..7b2e7bbb9bb4720d86f7a11a05c1edb3fa2a1ed3 100644
--- a/chrome/browser/sync/sessions/browser_list_router_helper.h
+++ b/chrome/browser/sync/sessions/browser_list_router_helper.h
@@ -18,7 +18,8 @@ namespace sync_sessions {
 class BrowserListRouterHelper : public chrome::BrowserListObserver,
                                 public TabStripModelObserver {
  public:
-  explicit BrowserListRouterHelper(SyncSessionsWebContentsRouter* router);
+  explicit BrowserListRouterHelper(SyncSessionsWebContentsRouter* router,
+                                   Profile* profile);
   ~BrowserListRouterHelper() override;
 
  private:
@@ -34,6 +35,10 @@ class BrowserListRouterHelper : public chrome::BrowserListObserver,
   // |router_| owns |this|.
   SyncSessionsWebContentsRouter* router_;
 
+  Profile* profile_;
+
+  std::set<Browser*> attached_browsers_;
+
   DISALLOW_COPY_AND_ASSIGN(BrowserListRouterHelper);
 };