Remove experimental comment on post_task.h and update comment about default traits.

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"
 #include "base/location.h"
 #include "base/memory/ref_counted.h"
 #include "base/post_task_and_reply_with_result_internal.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"
 #include "base/time/time.h"
 
 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.
 //
 // To post a simple one-off task:
 //     PostTask(FROM_HERE, Bind(...));
 //
 // To post a high priority one-off task to respond to a user interaction:
 //     PostTaskWithTraits(
 //         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 tasks that may block, must run in sequence and can be skipped on
 // shutdown:
 //     scoped_refptr<SequencedTaskRunner> task_runner =
 //         CreateSequencedTaskRunnerWithTraits(
 //             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
+//     (1) don't block (ref. MayBlock() and WithBaseSyncPrimitives()),
+//     (2) prefer inheriting the current priority to specifying their own, 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
 // PostTask[AndReply], otherwise override these with explicit traits via
 // PostTaskWithTraits[AndReply].
 //
 // Tasks posted to TaskScheduler with a delay may be coalesced (i.e. delays may
 // be adjusted to reduce the number of wakeups and hence power consumption).
 
 // Posts |task| to the TaskScheduler. Calling this is equivalent to calling
@@ skipping 95 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_