[BackgroundSync] Clean up some style nits and unnecessary checks

content/browser/background_sync/background_sync_manager.cc

Index: content/browser/background_sync/background_sync_manager.cc
diff --git a/content/browser/background_sync/background_sync_manager.cc b/content/browser/background_sync/background_sync_manager.cc
index 1a0432bc11391ac396d36ddc91baf18590dea2f1..938a87b92513f166f18332679e7dbe667a7f0bcb 100644
--- a/content/browser/background_sync/background_sync_manager.cc
+++ b/content/browser/background_sync/background_sync_manager.cc
@@ -1034,8 +1034,9 @@ void BackgroundSyncManager::EventCompleteImpl(
       RefCountedRegistration* active_registration =
           LookupActiveRegistration(service_worker_id, key);
       if (active_registration &&
-          active_registration->value()->id() == registration->id())
+          active_registration->value()->id() == registration->id()) {
         RemoveActiveRegistration(service_worker_id, key);
+      }
     }
   } else {
     // TODO(jkarlin): Add support for running periodic syncs. (crbug.com/479674)