Revert of Allow silent update for default-installed apps.

Revert of Allow silent update for default-installed apps. (patchset #1 id:1 of https://codereview.chromium.org/863743002/)

Reason for revert:
After landing, we've decided there's a better way to do this. The change history on the bug will be less confusing if we just revert this change first.

Original issue's description:
> Allow silent update for default-installed apps.
>
> This suppresses the automatic-disabling and requirement for
> explicit user consent when upgrading the permissions of
> a default-installed app.
>
> BUG=450300
> R=asargent@chromium.org
>
> Committed: https://crrev.com/92c7f7b3d0974547a628b5d21838c20b0f37839a
> Cr-Commit-Position: refs/heads/master@{#316608}

TBR=asargent@chromium.org,kalman@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=450300
Committed: https://crrev.com/f2723111c67173dec1a2fdb4e94bc61256101489
Cr-Commit-Position: refs/heads/master@{#316612}

[Ken Rockot(use gerrit already), 2015-02-17 18:29:56]

Created Revert of Allow silent update for default-installed apps.

[commit-bot: I haz the power, 2015-02-17 18:30:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/935663002/1

[commit-bot: I haz the power, 2015-02-17 18:31:50]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-17 18:32:48]

Patchset 1 (id:??) landed as
https://crrev.com/f2723111c67173dec1a2fdb4e94bc61256101489
Cr-Commit-Position: refs/heads/master@{#316612}