Automated IWYU fix for TaskRunner includes.

ios/chrome/browser/net/chrome_cookie_store_ios_client.h

 // Copyright 2014 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 IOS_CHROME_BROWSER_NET_CHROME_COOKIE_STORE_IOS_CLIENT_H_
 #define IOS_CHROME_BROWSER_NET_CHROME_COOKIE_STORE_IOS_CLIENT_H_
 
 #include "base/macros.h"
+#include "base/sequenced_task_runner.h"
 #include "base/threading/thread_checker.h"
 #include "ios/net/cookies/cookie_store_ios_client.h"
 
 @protocol BrowsingDataChangeListening;
 
 // Chrome implementation of net::CookieStoreIOSClient. This class lives on the
 // IOThread.
 class ChromeCookieStoreIOSClient : public net::CookieStoreIOSClient {
  public:
   // Creates a CookieStoreIOSClient with a BrowsingDataChangeListening.
   // |browsing_data_change_listener| cannot be nil.
   explicit ChromeCookieStoreIOSClient(
       id<BrowsingDataChangeListening> browsing_data_change_listener);
 
   // CookieStoreIOSClient implementation.
   void DidChangeCookieStorage() const override;
   scoped_refptr<base::SequencedTaskRunner> GetTaskRunner() const override;
 
  private:
   base::ThreadChecker thread_checker_;
   // The listener that is informed of change in browsing data.
   id<BrowsingDataChangeListening> browsing_data_change_listener_;  // Weak.
   DISALLOW_COPY_AND_ASSIGN(ChromeCookieStoreIOSClient);
 };
 
 #endif  // IOS_CHROME_BROWSER_NET_CHROME_COOKIE_STORE_IOS_CLIENT_H_