Remove deprecated methods TaskTraits::WithFileIO()/WithWait().

base/task_scheduler/post_task.h

 // Copyright 2016 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 BASE_TASK_SCHEDULER_POST_TASK_H_
 #define BASE_TASK_SCHEDULER_POST_TASK_H_
 
 #include "base/base_export.h"
 #include "base/bind.h"
 #include "base/callback_forward.h"
@@ skipping 23 matching lines @@
 //         FROM_HERE,
 //         TaskTraits().WithPriority(TaskPriority::USER_BLOCKING),
 //         Bind(...));
 //
 // To post tasks that must run in sequence:
 //     scoped_refptr<SequencedTaskRunner> task_runner =
 //         CreateSequencedTaskRunnerWithTraits(TaskTraits());
 //     task_runner.PostTask(FROM_HERE, Bind(...));
 //     task_runner.PostTask(FROM_HERE, Bind(...));
 //
-// To post file I/O tasks that must run in sequence and can be skipped on
+// To post tasks that may block, must run in sequence and can be skipped on
 // shutdown:
 //     scoped_refptr<SequencedTaskRunner> task_runner =
 //         CreateSequencedTaskRunnerWithTraits(
-//             TaskTraits().WithFileIO().WithShutdownBehavior(
+//             TaskTraits().MayBlock().WithShutdownBehavior(
 //                 TaskShutdownBehavior::SKIP_ON_SHUTDOWN));
 //     task_runner.PostTask(FROM_HERE, Bind(...));
 //     task_runner.PostTask(FROM_HERE, Bind(...));
 //
 // The default TaskTraits apply to tasks that:
 //     (1) don't need to do I/O,
 //     (2) don't affect user interaction and/or visible elements, and
 //     (3) can either block shutdown or be skipped on shutdown
 //         (barring current TaskScheduler default).
 // If those loose requirements are sufficient for your task, use
@@ skipping 82 matching lines @@
 // CreateSequencedTaskRunnerWithTraits(). Only use this if you rely on a thread-
 // affine API (it might be safer to assume thread-affinity when dealing with
 // under-documented third-party APIs, e.g. other OS') or share data across tasks
 // using thread-local storage.
 BASE_EXPORT scoped_refptr<SingleThreadTaskRunner>
 CreateSingleThreadTaskRunnerWithTraits(const TaskTraits& traits);
 
 }  // namespace base
 
 #endif  // BASE_TASK_SCHEDULER_POST_TASK_H_