Remove redundant null check for AudioBus

Remove redundant null check for AudioBus

In HTMLMediaElement::AudioSourceProviderImpl::provideInput there is an
assert as well as null check for AudioBus. At the call site
MediaElementAudioSourceHandler::process() AudioBus is directly used
without any validation. So it is enough to keep the assert and remove
the null check for AudioBus.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=199899

[Srirama, 2015-08-03 11:40:12]

srirama.m@samsung.com changed reviewers:
+ philipj@opera.com

[Srirama, 2015-08-03 11:40:12]

PTAL

[philipj_slow, 2015-08-03 11:45:27]

philipj@opera.com changed reviewers:
+ rtoy@chromium.org

[philipj_slow, 2015-08-03 11:45:27]

LGTM if rtoy@ things it's OK.

[Raymond Toy, 2015-08-03 15:38:00]

On 2015/08/03 11:45:27, philipj wrote:
> LGTM if rtoy@ things it's OK.

lgtm too.

[Srirama, 2015-08-03 16:26:08]

The CQ bit was checked by srirama.m@samsung.com

[commit-bot: I haz the power, 2015-08-03 16:26:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1269483004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1269483004/1

[commit-bot: I haz the power, 2015-08-03 16:29:43]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=199899