Revert of Enable multiprocess by default on desktop mojo_runner.

Revert of Enable multiprocess by default on desktop mojo_runner. (patchset #7 id:120001 of https://codereview.chromium.org/1434563004/ )

Reason for revert:
This is failing on CQ and waterfall now. It might have conflicted with another patch that landed in the meantime.

Original issue's description:
> Enable multiprocess by default on desktop mojo_runner.
>
> This makes apptests also run in multiprocess and use the new EDK as well.
>
> BUG=478251, 546644, 551083
>
> Committed: https://crrev.com/14d2827bffed6b8c4928001eb42d9f4dda23dd81
> Cr-Commit-Position: refs/heads/master@{#358664}

TBR=sky@chromium.org,msw@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=478251, 546644, 551083
Committed: https://crrev.com/5a930985c25d09084206c33bebbb2b60e65f2fd8
Cr-Commit-Position: refs/heads/master@{#358703}

[jam, 2015-11-09 23:27:47]

Created Revert of Enable multiprocess by default on desktop mojo_runner.

[commit-bot: I haz the power, 2015-11-09 23:30:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1423723007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1423723007/1

[commit-bot: I haz the power, 2015-11-09 23:35:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1423723007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1423723007/1

[commit-bot: I haz the power, 2015-11-09 23:37:17]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-09 23:37:59]

Patchset 1 (id:??) landed as
https://crrev.com/5a930985c25d09084206c33bebbb2b60e65f2fd8
Cr-Commit-Position: refs/heads/master@{#358703}