Mojo C++ bindings: fix Connector teardown.

Mojo C++ bindings: fix Connector teardown.

It is allowed to disconnect a Connector instance (by CloseMessagePipe() or
PassMessagePipe()) on the creation thread, and then destroy the instance on any
thread. However, without this fix it doesn't work because a Connector instance
still has got WeakPtr and mojo::Watcher bound to the creation thread.

BUG=594244
Committed: https://crrev.com/65085d5fe6a009f01d7630c2905f19e32104ef7c
Cr-Commit-Position: refs/heads/master@{#419626}

[yzshen1, 2016-09-19 22:21:37]

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

[commit-bot: I haz the power, 2016-09-19 22:21:58]

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

[yzshen1, 2016-09-19 22:22:04]

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

[yzshen1, 2016-09-19 22:22:04]

Hi, Ken.

Would you please take a look? Thanks!

[Ken Rockot(use gerrit already), 2016-09-19 22:53:57]

lgtm

[yzshen1, 2016-09-19 23:21:35]

The CQ bit was checked by yzshen@chromium.org

[commit-bot: I haz the power, 2016-09-19 23:21:52]

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, 2016-09-20 01:25:25]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-20 01:29:13]

Description was changed from

==========
Mojo C++ bindings: fix Connector teardown.

It is allowed to disconnect a Connector instance (by CloseMessagePipe() or
PassMessagePipe()) on the creation thread, and then destroy the instance on any
thread. However, without this fix it doesn't work because a Connector instance
still has got WeakPtr and mojo::Watcher bound to the creation thread.

BUG=594244
==========

to

==========
Mojo C++ bindings: fix Connector teardown.

It is allowed to disconnect a Connector instance (by CloseMessagePipe() or
PassMessagePipe()) on the creation thread, and then destroy the instance on any
thread. However, without this fix it doesn't work because a Connector instance
still has got WeakPtr and mojo::Watcher bound to the creation thread.

BUG=594244

Committed: https://crrev.com/65085d5fe6a009f01d7630c2905f19e32104ef7c
Cr-Commit-Position: refs/heads/master@{#419626}
==========

[commit-bot: I haz the power, 2016-09-20 01:29:14]

Patchset 1 (id:??) landed as
https://crrev.com/65085d5fe6a009f01d7630c2905f19e32104ef7c
Cr-Commit-Position: refs/heads/master@{#419626}