Automated IWYU fix for TaskRunner includes.

chrome/browser/password_manager/password_store_x.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_PASSWORD_MANAGER_PASSWORD_STORE_X_H_
 #define CHROME_BROWSER_PASSWORD_MANAGER_PASSWORD_STORE_X_H_
 
 #include <stddef.h>
 
 #include <memory>
 #include <vector>
 
 #include "base/macros.h"
+#include "base/single_thread_task_runner.h"
 #include "base/time/time.h"
 #include "components/password_manager/core/browser/password_store_default.h"
 
 namespace password_manager {
 class LoginDatabase;
 }
 
 // PasswordStoreX is used on Linux and other non-Windows, non-Mac OS X
 // operating systems. It uses a "native backend" to actually store the password
 // data when such a backend is available, and otherwise falls back to using the
@@ skipping 122 matching lines @@
   // Whether we should allow falling back to the default store. If there is
   // nothing to migrate, then the first attempt to use the native store will
   // be the first time we try to use it and we should allow falling back. If
   // we have migrated successfully, then we do not allow falling back.
   bool allow_fallback_;
 
   DISALLOW_COPY_AND_ASSIGN(PasswordStoreX);
 };
 
 #endif  // CHROME_BROWSER_PASSWORD_MANAGER_PASSWORD_STORE_X_H_