AudioRendererImpl: Don't advance time when rendering stops.

AudioRendererImpl: Don't advance time when rendering stops.

This is a quick work-around for the bug below. AudioRendererImpl was
recently improved to estimate time's advancing along the last rendered
audio buffer between Render() calls. This means the clock is capable of
still advancing a bit after OnBufferingStateChange indicates we've run
out of data. While tehcnically correct, the clocks advancing causes
blink to emit 'timeupdate' events with time advancing after emitting
'waiting' indicating that no data is buffered. This change stops the
clock once the render has underflowed.

Longterm, blink should be improved to gaurd against emitting timeupdate
after waiting. This larger change will be done separately to give it
time to bake. https://codereview.chromium.org/2425463002/

BUG=648710
Committed: https://crrev.com/9409db28cd7402d4bad8022afbd2b3719de72d08
Cr-Commit-Position: refs/heads/master@{#425871}

[chcunningham, 2016-10-17 23:20:55]

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

[commit-bot: I haz the power, 2016-10-17 23:21:35]

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

[chcunningham, 2016-10-17 23:26:03]

chcunningham@chromium.org changed reviewers:
+ sandersd@chromium.org

[sandersd (OOO until July 31), 2016-10-17 23:37:37]

lgtm

https://codereview.chromium.org/2423903003/diff/20001/media/renderers/audio_r...
File media/renderers/audio_renderer_impl.cc (right):

https://codereview.chromium.org/2423903003/diff/20001/media/renderers/audio_r...
media/renderers/audio_renderer_impl.cc:182: // layer (avoid currentTime
advancing while after signaling buffer underflow).
Remove 'while'.

https://codereview.chromium.org/2423903003/diff/20001/media/renderers/audio_r...
File media/renderers/audio_renderer_impl.h (right):

https://codereview.chromium.org/2423903003/diff/20001/media/renderers/audio_r...
media/renderers/audio_renderer_impl.h:294: base::TimeDelta last_media_time_;
Nit: Suggest |last_reported_media_time_| instead for code clarity.

[chcunningham, 2016-10-17 23:49:17]

Thanks!

https://codereview.chromium.org/2423903003/diff/20001/media/renderers/audio_r...
File media/renderers/audio_renderer_impl.cc (right):

https://codereview.chromium.org/2423903003/diff/20001/media/renderers/audio_r...
media/renderers/audio_renderer_impl.cc:182: // layer (avoid currentTime
advancing while after signaling buffer underflow).
On 2016/10/17 23:37:37, sandersd wrote:
> Remove 'while'.

Done.

https://codereview.chromium.org/2423903003/diff/20001/media/renderers/audio_r...
File media/renderers/audio_renderer_impl.h (right):

https://codereview.chromium.org/2423903003/diff/20001/media/renderers/audio_r...
media/renderers/audio_renderer_impl.h:294: base::TimeDelta last_media_time_;
On 2016/10/17 23:37:37, sandersd wrote:
> Nit: Suggest |last_reported_media_time_| instead for code clarity.

Done.

[chcunningham, 2016-10-17 23:49:29]

The CQ bit was checked by chcunningham@chromium.org

[chcunningham, 2016-10-17 23:49:29]

The patchset sent to the CQ was uploaded after l-g-t-m from
sandersd@chromium.org
Link to the patchset: https://codereview.chromium.org/2423903003/#ps40001
(title: "feedback")

[commit-bot: I haz the power, 2016-10-17 23:50:20]

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, 2016-10-18 02:50:25]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-10-18 02:52:31]

Description was changed from

==========
AudioRendererImpl: Don't advance time when rendering stops.

This is a quick work-around for the bug below. AudioRendererImpl was
recently improved to estimate time's advancing along the last rendered
audio buffer between Render() calls. This means the clock is capable of
still advancing a bit after OnBufferingStateChange indicates we've run
out of data. While tehcnically correct, the clocks advancing causes
blink to emit 'timeupdate' events with time advancing after emitting
'waiting' indicating that no data is buffered. This change stops the
clock once the render has underflowed.

Longterm, blink should be improved to gaurd against emitting timeupdate
after waiting. This larger change will be done separately to give it
time to bake. https://codereview.chromium.org/2425463002/

BUG=648710
==========

to

==========
AudioRendererImpl: Don't advance time when rendering stops.

This is a quick work-around for the bug below. AudioRendererImpl was
recently improved to estimate time's advancing along the last rendered
audio buffer between Render() calls. This means the clock is capable of
still advancing a bit after OnBufferingStateChange indicates we've run
out of data. While tehcnically correct, the clocks advancing causes
blink to emit 'timeupdate' events with time advancing after emitting
'waiting' indicating that no data is buffered. This change stops the
clock once the render has underflowed.

Longterm, blink should be improved to gaurd against emitting timeupdate
after waiting. This larger change will be done separately to give it
time to bake. https://codereview.chromium.org/2425463002/

BUG=648710

Committed: https://crrev.com/9409db28cd7402d4bad8022afbd2b3719de72d08
Cr-Commit-Position: refs/heads/master@{#425871}
==========

[commit-bot: I haz the power, 2016-10-18 02:52:31]

Patchset 3 (id:??) landed as
https://crrev.com/9409db28cd7402d4bad8022afbd2b3719de72d08
Cr-Commit-Position: refs/heads/master@{#425871}