Revert of Supervised user SafeSites: Expose & use API key from src-internal

Revert of Supervised user SafeSites: Expose & use API key from src-internal (patchset #5 id:80001 of https://codereview.chromium.org/690423003/)

Reason for revert:
Build breakage on Mac:

https://build.chromium.org/p/chromium.mac/builders/Mac%20Builder/builds/14318/steps/steps/logs/stdio

Original issue's description:
> Supervised user SafeSites: Expose & use API key from src-internal
>
> Key was added to src-internal in https://chromereviews.googleplex.com/113767014/
>
> BUG=417722
>
> Committed: https://crrev.com/2ee5f146d57d07bbad3804715e06590b850711f9
> Cr-Commit-Position: refs/heads/master@{#305412}

TBR=rogerta@chromium.org,bauerb@chromium.org,treib@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=417722
Committed: https://crrev.com/13c88c66f60e6364478a411e8ccf0bfd689f0a96
Cr-Commit-Position: refs/heads/master@{#305413}

[Thiemo Nagel, 2014-11-24 11:32:33]

Created Revert of Supervised user SafeSites: Expose & use API key from
src-internal

[commit-bot: I haz the power, 2014-11-24 11:32:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/753683004/1

[commit-bot: I haz the power, 2014-11-24 11:33:07]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-11-24 11:34:00]

Patchset 1 (id:??) landed as
https://crrev.com/13c88c66f60e6364478a411e8ccf0bfd689f0a96
Cr-Commit-Position: refs/heads/master@{#305413}

[Marc Treib, 2014-11-24 12:33:56]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/756593002/ by treib@chromium.org.

The reason for reverting is: Relanding because the original reason for reverting
looks like a flake rather than an issue with the CL..