[chrome.displaySource] Consolidate media pipeline initialization.

[chrome.displaySource] Consolidate media pipeline initialization.

This consolidates orchestration of media pipeline initialization steps
into one function. That makes it easier to add new steps and to change
order of the steps. This does not change the functionality of the media
pipeline.

BUG=242107
Committed: https://crrev.com/17f325f176e61ef4eb4f8cb47ff387411fb0b084
Cr-Commit-Position: refs/heads/master@{#389045}

[e_hakkinen, 2016-04-20 18:34:31]

eero.hakkinen@intel.com changed reviewers:
+ alexander.shalamov@intel.com, asargent@chromium.org,
mikhail.pozdnyakov@intel.com

[e_hakkinen, 2016-04-20 18:34:31]

PTAL. This should simplify further modification of media pipeline
initialisation.

[Mikhail, 2016-04-20 19:00:42]

lgtm

[asargent_no_longer_on_chrome, 2016-04-21 19:55:51]

lgtm

[Mikhail, 2016-04-22 06:00:48]

The CQ bit was checked by mikhail.pozdnyakov@intel.com

[commit-bot: I haz the power, 2016-04-22 06:01:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1908563002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1908563002/1

[commit-bot: I haz the power, 2016-04-22 06:38:25]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-22 19:45:03]

Description was changed from

==========
[chrome.displaySource] Consolidate media pipeline initialization.

This consolidates orchestration of media pipeline initialization steps
into one function. That makes it easier to add new steps and to change
order of the steps. This does not change the functionality of the media
pipeline.

BUG=242107
==========

to

==========
[chrome.displaySource] Consolidate media pipeline initialization.

This consolidates orchestration of media pipeline initialization steps
into one function. That makes it easier to add new steps and to change
order of the steps. This does not change the functionality of the media
pipeline.

BUG=242107

Committed: https://crrev.com/17f325f176e61ef4eb4f8cb47ff387411fb0b084
Cr-Commit-Position: refs/heads/master@{#389045}
==========

[commit-bot: I haz the power, 2016-04-22 19:45:06]

Patchset 1 (id:??) landed as
https://crrev.com/17f325f176e61ef4eb4f8cb47ff387411fb0b084
Cr-Commit-Position: refs/heads/master@{#389045}