Automated IWYU fix for TaskRunner includes.

ios/chrome/browser/net/ios_chrome_url_request_context_getter.h

 // Copyright 2015 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_IOS_CHROME_URL_REQUEST_CONTEXT_GETTER_H_
 #define IOS_CHROME_BROWSER_NET_IOS_CHROME_URL_REQUEST_CONTEXT_GETTER_H_
 
 #include <memory>
 
 #include "base/macros.h"
+#include "base/single_thread_task_runner.h"
 #include "ios/chrome/browser/net/net_types.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
 
 class ChromeBrowserStateIOData;
 class IOSChromeURLRequestContextFactory;
 
 // A net::URLRequestContextGetter subclass used by the browser. This returns a
 // subclass of net::URLRequestContext which can be used to store extra
 // information about requests.
@@ skipping 43 matching lines @@
   // NULL before initialization and after invalidation.
   // Otherwise, it is the URLRequestContext instance that
   // was lazily created by GetURLRequestContext().
   // Access only from the IO thread.
   net::URLRequestContext* url_request_context_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSChromeURLRequestContextGetter);
 };
 
 #endif  // IOS_CHROME_BROWSER_NET_IOS_CHROME_URL_REQUEST_CONTEXT_GETTER_H_