Update last audio tick time during suspend and resume.

Update last audio tick time during suspend and resume.

If someone suspends their computer and resumes more than a minute
later, the browser io thread may tick before the audio thread can
update the last tick time ==> crash :(

The solution is to disable hang detection during suspend and only
reenable it once resume completes; at which point we can update
the tick count. If we're actually hung, we'll crash after the next
interval elapses.

BUG=471046
TEST=none

Committed: https://crrev.com/615510b0a769e83e36e1d1fb27465abb74bed6b4
Cr-Commit-Position: refs/heads/master@{#322509}

[DaleCurtis, 2015-03-26 22:03:21]

dalecurtis@chromium.org changed reviewers:
+ nasko@chromium.org

[nasko, 2015-03-26 23:10:44]

https://codereview.chromium.org/1036933003/diff/1/media/audio/audio_manager.cc
File media/audio/audio_manager.cc (right):

https://codereview.chromium.org/1036933003/diff/1/media/audio/audio_manager.c...
media/audio/audio_manager.cc:42: void OnResume() override {
Are we guaranteed that there will be no task execution between resuming and this
call? I wonder if this notification is done after executing some existing tasks
on the message loop, because that has the potential to cause the delayed crash
task to execute before the resume handler has run. Maybe add a guard boolean
that we set on suspend and reset on resume?

https://codereview.chromium.org/1036933003/diff/1/media/audio/audio_manager.c...
media/audio/audio_manager.cc:43: OnSuspend();
nit: Why not add a private method that does the work and call it from both
observer methods? Calling OnSuspend handler when resuming is ... awkward.

[DaleCurtis, 2015-03-26 23:26:45]

https://codereview.chromium.org/1036933003/diff/1/media/audio/audio_manager.cc
File media/audio/audio_manager.cc (right):

https://codereview.chromium.org/1036933003/diff/1/media/audio/audio_manager.c...
media/audio/audio_manager.cc:42: void OnResume() override {
On 2015/03/26 23:10:43, nasko wrote:
> Are we guaranteed that there will be no task execution between resuming and
this
> call? I wonder if this notification is done after executing some existing
tasks
> on the message loop, because that has the potential to cause the delayed crash
> task to execute before the resume handler has run. Maybe add a guard boolean
> that we set on suspend and reset on resume? 

Ah, I was going to do this, but thought it wasn't any better than what I have
now, but thinking about it more, you're right, it's better. Done!

https://codereview.chromium.org/1036933003/diff/1/media/audio/audio_manager.c...
media/audio/audio_manager.cc:43: OnSuspend();
On 2015/03/26 23:10:44, nasko wrote:
> nit: Why not add a private method that does the work and call it from both
> observer methods? Calling OnSuspend handler when resuming is ... awkward.

No need anymore.

[nasko, 2015-03-26 23:35:11]

LGTM

[DaleCurtis, 2015-03-26 23:40:28]

The CQ bit was checked by dalecurtis@chromium.org

[commit-bot: I haz the power, 2015-03-26 23:40:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1036933003/20001

[commit-bot: I haz the power, 2015-03-27 00:30:52]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-27 00:31:42]

Patchset 2 (id:??) landed as
https://crrev.com/615510b0a769e83e36e1d1fb27465abb74bed6b4
Cr-Commit-Position: refs/heads/master@{#322509}