Document TaskRunners/TaskTraits/FROM_HERE as implicitly included from post_task.h

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/callback_forward.h"
 #include "base/location.h"
 #include "base/memory/ref_counted.h"
 #include "base/sequenced_task_runner.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner.h"
 #include "base/task_scheduler/task_traits.h"
 
+// To avoid redundant includes: users may omit including the following headers
+// if they are using their provided data types solely in direct interactions
+// with this API: location.h, task_traits.h, and *task_runner.h.

[robliao, 2016/11/02 20:13:55]

Is the asterisk in task_runner.h intentional?

[gab, 2016/11/02 20:25:21]

Yes, it applies to all 3 TaskRunner headers.

[danakj, 2016/11/02 22:58:01]

I think this comment is overprescribing things, just use the right includes and
let users do as they will.

+
 namespace base {
 
 // This is the preferred interface to post tasks to the TaskScheduler.
 //
 // Note: The TaskScheduler is still in an experimental phase in Chrome. Please
 // refrain from using this API unless you know what you are doing.
 //
 // TaskScheduler must have been registered for the current process via
 // TaskScheduler::SetInstance() before the functions below are valid.
 //
@@ skipping 78 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_