Remove content::kFontListSequenceToken.

content/browser/font_list_async.cc

 // Copyright (c) 2011 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.
 
 #include "content/public/browser/font_list_async.h"
 
 #include <utility>
 
 #include "base/bind.h"
+#include "base/task_runner_util.h"
 #include "base/values.h"
 #include "content/common/font_list.h"
-#include "content/public/browser/browser_thread.h"
 
 namespace content {
 
-namespace {
-
-// Just executes the given callback with the parameter.
-void ReturnFontListToOriginalThread(
-    const base::Callback<void(std::unique_ptr<base::ListValue>)>& callback,
-    std::unique_ptr<base::ListValue> result) {
-  callback.Run(std::move(result));
-}
-
-void GetFontListInBlockingPool(
-    BrowserThread::ID calling_thread_id,
-    const base::Callback<void(std::unique_ptr<base::ListValue>)>& callback) {
-  std::unique_ptr<base::ListValue> result(GetFontList_SlowBlocking());
-  BrowserThread::PostTask(calling_thread_id, FROM_HERE,
-      base::Bind(&ReturnFontListToOriginalThread, callback,
-                 base::Passed(&result)));
-}
-
-}  // namespace
-
 void GetFontListAsync(
-    const base::Callback<void(std::unique_ptr<base::ListValue>)>& callback) {
-  BrowserThread::ID id;
-  bool well_known_thread = BrowserThread::GetCurrentThreadIdentifier(&id);
-  DCHECK(well_known_thread)
-      << "Can only call GetFontList from a well-known thread.";
-
-  BrowserThread::PostBlockingPoolSequencedTask(
-      kFontListSequenceToken,
-      FROM_HERE,
-      base::Bind(&GetFontListInBlockingPool, id, callback));
+    base::OnceCallback<void(std::unique_ptr<base::ListValue>)> callback) {
+  base::PostTaskAndReplyWithResult(GetFontListTaskRunner().get(), FROM_HERE,
+                                   base::BindOnce(&GetFontList_SlowBlocking),
+                                   std::move(callback));
 }
 
 }  // namespace content