Use FileDescriptorWatcher in SerialIoHandlerPosix.

Use FileDescriptorWatcher in SerialIoHandlerPosix.

This allows SerialIoHandlerPosix to be used from any thread that
instantiates a FileDescriptorWatcher (not just threads that run
a MessageLoopForIO). This will facilitate the migration of
BrowserThreads to base/task_scheduler.

BUG=645114
Committed: https://crrev.com/fab0376d55393aabb6811c6cbdbe1f67975b13b4
Cr-Commit-Position: refs/heads/master@{#423883}

[fdoray, 2016-10-05 14:27:22]

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

[commit-bot: I haz the power, 2016-10-05 14:27:37]

Dry run: 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, 2016-10-05 15:10:52]

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

[commit-bot: I haz the power, 2016-10-05 15:10:53]

Dry run: This issue passed the CQ dry run.

[fdoray, 2016-10-05 15:19:04]

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

[fdoray, 2016-10-05 15:19:05]

PTAL

[Ken Rockot(use gerrit already), 2016-10-07 15:59:45]

lgtm

[fdoray, 2016-10-07 16:02:43]

The CQ bit was checked by fdoray@chromium.org

[commit-bot: I haz the power, 2016-10-07 16:03:08]

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, 2016-10-07 16:43:30]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-07 16:45:28]

Description was changed from

==========
Use FileDescriptorWatcher in SerialIoHandlerPosix.

This allows SerialIoHandlerPosix to be used from any thread that
instantiates a FileDescriptorWatcher (not just threads that run
a MessageLoopForIO). This will facilitate the migration of
BrowserThreads to base/task_scheduler.

BUG=645114
==========

to

==========
Use FileDescriptorWatcher in SerialIoHandlerPosix.

This allows SerialIoHandlerPosix to be used from any thread that
instantiates a FileDescriptorWatcher (not just threads that run
a MessageLoopForIO). This will facilitate the migration of
BrowserThreads to base/task_scheduler.

BUG=645114

Committed: https://crrev.com/fab0376d55393aabb6811c6cbdbe1f67975b13b4
Cr-Commit-Position: refs/heads/master@{#423883}
==========

[commit-bot: I haz the power, 2016-10-07 16:45:28]

Patchset 1 (id:??) landed as
https://crrev.com/fab0376d55393aabb6811c6cbdbe1f67975b13b4
Cr-Commit-Position: refs/heads/master@{#423883}