Remove MessageLoop::current() from socket_host_tcp.cc.

Remove MessageLoop::current() from socket_host_tcp.cc.

Whenever possible, use ThreadTaskRunnerHandle::Get() instead of
MessageLoop::current(). ThreadTaskRunnerHandle::Get() works within
TaskScheduler while MessageLoop::current() doesn't.

Good reasons to use MessageLoop::current():
- Add destruction, nesting or task observers.
- Run nested loops.

Bad reasons to use MessageLoop::current():
- Post tasks. Use ThreadTaskRunnerHandle::Get() instead.
- Watch a file descriptor. Use FileDescriptorWatcher instead.
- Verify that it is possible to post tasks to the current thread.
  Use ThreadTaskRunnerHandle::IsSet() instead.
- Verify that code runs on a specific thread. Use
  SingleThreadTaskRunner::BelongsToCurrentThread() instead.

BUG=650723
Committed: https://crrev.com/58cdcc5798f592aa748d73952b6fc785d7164666
Cr-Commit-Position: refs/heads/master@{#424718}

[fdoray, 2016-10-11 18:28:04]

The CQ bit was checked by fdoray@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-10-11 18:28:23]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[fdoray, 2016-10-11 19:42:41]

fdoray@chromium.org changed reviewers:
+ sergeyu@chromium.org

[fdoray, 2016-10-11 19:42:42]

PTAL

[Sergey Ulanov, 2016-10-11 20:13:17]

lgtm

[commit-bot: I haz the power, 2016-10-11 21:35:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-10-11 21:35:45]

Dry run: This issue passed the CQ dry run.

[fdoray, 2016-10-12 12:07:52]

The CQ bit was checked by fdoray@chromium.org

[commit-bot: I haz the power, 2016-10-12 12:07:59]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-12 12:13:22]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-12 12:15:00]

Description was changed from

==========
Remove MessageLoop::current() from socket_host_tcp.cc.

Whenever possible, use ThreadTaskRunnerHandle::Get() instead of
MessageLoop::current(). ThreadTaskRunnerHandle::Get() works within
TaskScheduler while MessageLoop::current() doesn't.

Good reasons to use MessageLoop::current():
- Add destruction, nesting or task observers.
- Run nested loops.

Bad reasons to use MessageLoop::current():
- Post tasks. Use ThreadTaskRunnerHandle::Get() instead.
- Watch a file descriptor. Use FileDescriptorWatcher instead.
- Verify that it is possible to post tasks to the current thread.
  Use ThreadTaskRunnerHandle::IsSet() instead.
- Verify that code runs on a specific thread. Use
  SingleThreadTaskRunner::BelongsToCurrentThread() instead.

BUG=650723
==========

to

==========
Remove MessageLoop::current() from socket_host_tcp.cc.

Whenever possible, use ThreadTaskRunnerHandle::Get() instead of
MessageLoop::current(). ThreadTaskRunnerHandle::Get() works within
TaskScheduler while MessageLoop::current() doesn't.

Good reasons to use MessageLoop::current():
- Add destruction, nesting or task observers.
- Run nested loops.

Bad reasons to use MessageLoop::current():
- Post tasks. Use ThreadTaskRunnerHandle::Get() instead.
- Watch a file descriptor. Use FileDescriptorWatcher instead.
- Verify that it is possible to post tasks to the current thread.
  Use ThreadTaskRunnerHandle::IsSet() instead.
- Verify that code runs on a specific thread. Use
  SingleThreadTaskRunner::BelongsToCurrentThread() instead.

BUG=650723

Committed: https://crrev.com/58cdcc5798f592aa748d73952b6fc785d7164666
Cr-Commit-Position: refs/heads/master@{#424718}
==========

[commit-bot: I haz the power, 2016-10-12 12:15:01]

Patchset 1 (id:??) landed as
https://crrev.com/58cdcc5798f592aa748d73952b6fc785d7164666
Cr-Commit-Position: refs/heads/master@{#424718}