Reland: "Sync: Support multiple setup UIs."

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 a95405c9dca252ef8a52c417d028b21b2b605b7e..8bd0dae64c80eeb7e004d18f1c9e2dc0717ad2dc 100644
--- a/chrome/browser/ui/sync/one_click_signin_sync_starter.h
+++ b/chrome/browser/ui/sync/one_click_signin_sync_starter.h
@@ -24,7 +24,11 @@ class ProfileSyncService;
 
 namespace content {
 class WebContents;
-}  // namespace content
+}
+
+namespace sync_driver {
+class SyncSetupInProgressHandle;
+}
 
 // Waits for successful sign-in notification from the signin manager and then
 // starts the sync machine.  Instances of this class delete themselves once
@@ -238,6 +242,9 @@ class OneClickSigninSyncStarter : public SigninTracker::Observer,
   // following AccountAddedToCookie calls triggered by account reconciliation.
   bool first_account_added_to_cookie_;
 
+  // Prevents Sync from running until configuration is complete.
+  std::unique_ptr<sync_driver::SyncSetupInProgressHandle> sync_blocker_;
+
   base::WeakPtrFactory<OneClickSigninSyncStarter> weak_pointer_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OneClickSigninSyncStarter);