Invalidate the weak factory in SpeechRecognizer::EventListener::StopOnIOThread().

Invalidate the weak factory in SpeechRecognizer::EventListener::StopOnIOThread().

When an |app_list::SpeechRecognizer| is destroyed, a callback to
SpeechRecognizer::EventListener::StopOnIOThread() is posted to the IO
thread, and the |SpeechRecognizer| releases it's reference to
|EventListener|. |EventListener| may have weak pointers that must be
invalidated on the IO thread. However, on |SpeechRecognizer| releasing
its reference, the callback may have already run and hence the
|EventListener| is deleted upon releasing that reference on the UI
thread. This change ensures there are no more weak references to
|EventListener| by the time it is destroyed.

BUG=547650
Committed: https://crrev.com/228f0a02c58c37e39099daf12d57488c25b328fe
Cr-Commit-Position: refs/heads/master@{#356008}

[Anand Mistry (off Chromium), 2015-10-26 02:50:48]

amistry@chromium.org changed reviewers:
+ mgiuca@chromium.org

[Matt Giuca, 2015-10-26 04:04:53]

OK I kind of get this but it's a little unclear from the description. Is there a
bug for this?

If not, could you file a bug, and go into a bit more detail about the problem
there, that would be sufficient.

lgtm.

[Anand Mistry (off Chromium), 2015-10-26 04:10:12]

Description was changed from

==========
Invalidate the weak factory in
SpeechRecognizer::EventListener::StopOnIOThread().

When an |app_list::SpeechRecognizer| is destroyed, a callback to
SpeechRecognizer::EventListener::StopOnIOThread() is posted to the IO
thread, and the |SpeechRecognizer| releases it's reference to
|EventListener|. |EventListener| may have weak pointers that must be
invalidated on the IO thread. However, on |SpeechRecognizer| releasing
its reference, the callback may have already run and hence the
|EventListener| is deleted upon releasing that reference on the UI
thread. This change ensures there are no more weak references to
|EventListener| by the time it is destroyed.
==========

to

==========
Invalidate the weak factory in
SpeechRecognizer::EventListener::StopOnIOThread().

When an |app_list::SpeechRecognizer| is destroyed, a callback to
SpeechRecognizer::EventListener::StopOnIOThread() is posted to the IO
thread, and the |SpeechRecognizer| releases it's reference to
|EventListener|. |EventListener| may have weak pointers that must be
invalidated on the IO thread. However, on |SpeechRecognizer| releasing
its reference, the callback may have already run and hence the
|EventListener| is deleted upon releasing that reference on the UI
thread. This change ensures there are no more weak references to
|EventListener| by the time it is destroyed.

BUG=547650
==========

[Anand Mistry (off Chromium), 2015-10-26 04:11:12]

Bug filed (it's a test flake).

[Anand Mistry (off Chromium), 2015-10-26 04:14:32]

The CQ bit was checked by amistry@chromium.org

[commit-bot: I haz the power, 2015-10-26 04:14:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1413403004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1413403004/1

[commit-bot: I haz the power, 2015-10-26 04:50:41]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-26 04:51:31]

Patchset 1 (id:??) landed as
https://crrev.com/228f0a02c58c37e39099daf12d57488c25b328fe
Cr-Commit-Position: refs/heads/master@{#356008}