Standardize usage of virtual/override/final specifiers in sync/.

sync/internal_api/sync_rollback_manager_base_unittest.cc

Index: sync/internal_api/sync_rollback_manager_base_unittest.cc
diff --git a/sync/internal_api/sync_rollback_manager_base_unittest.cc b/sync/internal_api/sync_rollback_manager_base_unittest.cc
index 2f682add6c31f8ecbaa55f1516e0a18a59201cbc..fd1c12f849d33d086dca50ac2f7aadd1edfad243 100644
--- a/sync/internal_api/sync_rollback_manager_base_unittest.cc
+++ b/sync/internal_api/sync_rollback_manager_base_unittest.cc
@@ -33,7 +33,7 @@ class SyncTestRollbackManager : public SyncRollbackManagerBase {
 
 class SyncRollbackManagerBaseTest : public testing::Test {
  protected:
-  virtual void SetUp() override {
+  void SetUp() override {
     SyncManager::InitArgs args;
     args.database_location = base::FilePath(base::FilePath::kCurrentDirectory);
     args.service_url = GURL("https://example.com/");