Standardize usage of virtual/override/final in chrome/browser/sync_file_system/

chrome/browser/sync_file_system/drive_backend/uninstall_app_task.h

Index: chrome/browser/sync_file_system/drive_backend/uninstall_app_task.h
diff --git a/chrome/browser/sync_file_system/drive_backend/uninstall_app_task.h b/chrome/browser/sync_file_system/drive_backend/uninstall_app_task.h
index ca2d59cd06dd7e96d4cf386efb001a29709b685b..e6baead377f1187cc8247857d1b00b58b480aeda 100644
--- a/chrome/browser/sync_file_system/drive_backend/uninstall_app_task.h
+++ b/chrome/browser/sync_file_system/drive_backend/uninstall_app_task.h
@@ -37,9 +37,9 @@ class UninstallAppTask : public ExclusiveTask {
   UninstallAppTask(SyncEngineContext* sync_context,
                    const std::string& app_id,
                    UninstallFlag uninstall_flag);
-  virtual ~UninstallAppTask();
+  ~UninstallAppTask() override;
 
-  virtual void RunExclusive(const SyncStatusCallback& callback) override;
+  void RunExclusive(const SyncStatusCallback& callback) override;
 
  private:
   void DidDeleteAppRoot(const SyncStatusCallback& callback,