Only handle the first AccountAddedToCookie event in OneClickSigninSyncStarter

chrome/browser/ui/sync/one_click_signin_sync_starter.h

Index: chrome/browser/ui/sync/one_click_signin_sync_starter.h
diff --git a/chrome/browser/ui/sync/one_click_signin_sync_starter.h b/chrome/browser/ui/sync/one_click_signin_sync_starter.h
index 5cc33693280cd3b14a79b0756c355bc203ec2cbd..b8b497071adc910c366fb25b2349da0eecd894cf 100644
--- a/chrome/browser/ui/sync/one_click_signin_sync_starter.h
+++ b/chrome/browser/ui/sync/one_click_signin_sync_starter.h
@@ -233,6 +233,11 @@ class OneClickSigninSyncStarter : public SigninTracker::Observer,
   std::string dm_token_;
   std::string client_id_;
 
+  // This only cares about the first AccountAddedToCookie event. Since
+  // SigninTracker always expects an observer, this object will just disregard
+  // following AccountAddedToCookie calls triggered by account reconciliation.
+  bool first_account_added_to_cookie_;
+
   base::WeakPtrFactory<OneClickSigninSyncStarter> weak_pointer_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OneClickSigninSyncStarter);