IME for Mus: Fix InputMethodMusTest.DispatchKeyEvent's deadlock.

IME for Mus: Fix InputMethodMusTest.DispatchKeyEvent's deadlock.

What was happening was:
 - IMEServerImpl starts test_ime_driver, which registers itself to Mus.
 - InputMethodMusTests requests to start test_ime_driver, but before it
   starts, it connects to IMEServer, which creates a connection between
   client and the first test_ime_driver.
 - test_ime_driver starts for a 2nd time, which causes IMEServerImpl to
   drop the connection to the first test_ime_driver. This causes
   clients using the first test_ime_driver to hang.

This fix:
 - Removes starting the test_ime_driver for a 2nd time.
 - Rejects drivers after first driver registers itself.

BUG=668181
Committed: https://crrev.com/c2edfc8753717dee68567dbb08f04e8623f1be65
Cr-Commit-Position: refs/heads/master@{#435291}

[Hadi, 2016-11-29 22:37:44]

Description was changed from

==========
implement.

BUG=
==========

to

==========
IME for Mus: Fix InputMethodMusTest.DispatchKeyEvent's deadlock.

What was happening was:
 - IMEServerImpl starts test_ime_driver, which registers itself to Mus.
 - InputMethodMusTests requests to start test_ime_driver, but before it
   starts, it connects to IMEServer, which creates a connection between
   client and the first test_ime_driver.
 - test_ime_driver starts for a 2nd time, which causes IMEServerImpl to
   drop the connection to the first test_ime_driver. This causes
   clients using the first test_ime_driver to hang.

This fix:
 - Removes starting the test_ime_driver for a 2nd time.
 - Rejects drivers after first driver registers itself.

BUG=668181
==========

[Hadi, 2016-11-29 22:38:02]

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

[Hadi, 2016-11-29 22:38:39]

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

[commit-bot: I haz the power, 2016-11-29 22:39:04]

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

[Hadi, 2016-11-29 22:45:52]

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

[commit-bot: I haz the power, 2016-11-29 22:46:37]

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

[Hadi, 2016-11-29 22:46:53]

moshayedi@chromium.org changed reviewers:
+ sky@chromium.org

[Hadi, 2016-11-29 22:46:54]

PTAL.

[sky, 2016-11-29 23:58:12]

LGTM

[Hadi, 2016-11-30 00:11:08]

The CQ bit was unchecked by moshayedi@chromium.org

[Hadi, 2016-11-30 00:11:13]

The CQ bit was checked by moshayedi@chromium.org

[commit-bot: I haz the power, 2016-11-30 00:12:07]

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, 2016-11-30 00:48:20]

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

[commit-bot: I haz the power, 2016-11-30 00:48:21]

Try jobs failed on following builders:
  chromeos_daisy_chromium_compile_only_ng on master.tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)
  chromeos_x86-generic_chromium_compile_only_ng on
master.tryserver.chromium.linux (JOB_TIMED_OUT, no build URL)
  linux_chromium_chromeos_compile_dbg_ng on master.tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)
  linux_chromium_chromeos_ozone_rel_ng on master.tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)

[Hadi, 2016-11-30 02:06:07]

The CQ bit was checked by moshayedi@chromium.org

[commit-bot: I haz the power, 2016-11-30 02:06:52]

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

[Hadi, 2016-11-30 02:08:45]

The CQ bit was unchecked by moshayedi@chromium.org

[Hadi, 2016-11-30 15:37:57]

The CQ bit was checked by moshayedi@chromium.org

[Hadi, 2016-11-30 15:37:57]

The patchset sent to the CQ was uploaded after l-g-t-m from sky@chromium.org
Link to the patchset: https://codereview.chromium.org/2535403002/#ps60001
(title: ".")

[commit-bot: I haz the power, 2016-11-30 15:38:28]

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, 2016-11-30 16:45:04]

CQ is committing da patch.

Bot data: {"patchset_id": 60001, "attempt_start_ts": 1480520277464060,
"parent_rev": "56eb86e7cac9368476269fdfa3f0f9f570c68ed7", "commit_rev":
"3ec37e4c21c978211ef63e703042ab084ff25d08"}

[commit-bot: I haz the power, 2016-11-30 16:45:32]

Description was changed from

==========
IME for Mus: Fix InputMethodMusTest.DispatchKeyEvent's deadlock.

What was happening was:
 - IMEServerImpl starts test_ime_driver, which registers itself to Mus.
 - InputMethodMusTests requests to start test_ime_driver, but before it
   starts, it connects to IMEServer, which creates a connection between
   client and the first test_ime_driver.
 - test_ime_driver starts for a 2nd time, which causes IMEServerImpl to
   drop the connection to the first test_ime_driver. This causes
   clients using the first test_ime_driver to hang.

This fix:
 - Removes starting the test_ime_driver for a 2nd time.
 - Rejects drivers after first driver registers itself.

BUG=668181
==========

to

==========
IME for Mus: Fix InputMethodMusTest.DispatchKeyEvent's deadlock.

What was happening was:
 - IMEServerImpl starts test_ime_driver, which registers itself to Mus.
 - InputMethodMusTests requests to start test_ime_driver, but before it
   starts, it connects to IMEServer, which creates a connection between
   client and the first test_ime_driver.
 - test_ime_driver starts for a 2nd time, which causes IMEServerImpl to
   drop the connection to the first test_ime_driver. This causes
   clients using the first test_ime_driver to hang.

This fix:
 - Removes starting the test_ime_driver for a 2nd time.
 - Rejects drivers after first driver registers itself.

BUG=668181
==========

[commit-bot: I haz the power, 2016-11-30 16:45:34]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2016-11-30 16:50:13]

Description was changed from

==========
IME for Mus: Fix InputMethodMusTest.DispatchKeyEvent's deadlock.

What was happening was:
 - IMEServerImpl starts test_ime_driver, which registers itself to Mus.
 - InputMethodMusTests requests to start test_ime_driver, but before it
   starts, it connects to IMEServer, which creates a connection between
   client and the first test_ime_driver.
 - test_ime_driver starts for a 2nd time, which causes IMEServerImpl to
   drop the connection to the first test_ime_driver. This causes
   clients using the first test_ime_driver to hang.

This fix:
 - Removes starting the test_ime_driver for a 2nd time.
 - Rejects drivers after first driver registers itself.

BUG=668181
==========

to

==========
IME for Mus: Fix InputMethodMusTest.DispatchKeyEvent's deadlock.

What was happening was:
 - IMEServerImpl starts test_ime_driver, which registers itself to Mus.
 - InputMethodMusTests requests to start test_ime_driver, but before it
   starts, it connects to IMEServer, which creates a connection between
   client and the first test_ime_driver.
 - test_ime_driver starts for a 2nd time, which causes IMEServerImpl to
   drop the connection to the first test_ime_driver. This causes
   clients using the first test_ime_driver to hang.

This fix:
 - Removes starting the test_ime_driver for a 2nd time.
 - Rejects drivers after first driver registers itself.

BUG=668181

Committed: https://crrev.com/c2edfc8753717dee68567dbb08f04e8623f1be65
Cr-Commit-Position: refs/heads/master@{#435291}
==========

[commit-bot: I haz the power, 2016-11-30 16:50:14]

Patchset 4 (id:??) landed as
https://crrev.com/c2edfc8753717dee68567dbb08f04e8623f1be65
Cr-Commit-Position: refs/heads/master@{#435291}