[sync] Display an error when sync settings aren't confirmed

components/browser_sync/profile_sync_service.h

Index: components/browser_sync/profile_sync_service.h
diff --git a/components/browser_sync/profile_sync_service.h b/components/browser_sync/profile_sync_service.h
index 6c6a408857785a5a41e6e74bec201331086649d1..ddc7d6b0ca2832024a9803336840119c1b63b45a 100644
--- a/components/browser_sync/profile_sync_service.h
+++ b/components/browser_sync/profile_sync_service.h
@@ -435,6 +435,10 @@ class ProfileSyncService : public syncer::SyncServiceBase,
   // Returns whether sync is currently allowed on this platform.
   bool IsSyncAllowedByPlatform() const;
 
+  // Whether sync is currently blocked from starting because the sync
+  // confirmation dialog hasn't been confirmed.
+  bool IsSyncConfirmationNeeded() const;
+
   // Returns whether sync is managed, i.e. controlled by configuration
   // management. If so, the user is not allowed to configure sync.
   virtual bool IsManaged() const;