Revert of Use standard ICE in Chromoting.

Revert of Use standard ICE in Chromoting. (patchset #7 id:160001 of https://codereview.chromium.org/1085703003/)

Reason for revert:
This change did cause test failure: http://build.chromium.org/p/chromium.memory.fyi/builders/Chromium%20Mac%20%28valgrind%29%282%29/builds/34169/ (the link in the first revert was incorrect)

Original issue's description:
> Use standard ICE in Chromoting.
>
> Previously we were using legacy, non-standard version of ICE. This
> change adds ICE version negotiation and enabled standard ICE by default,
> when both peers support it.
>
> BUG=473758
>
> Committed: https://crrev.com/5a5854ee3e1c5760b422f26d31909bfb5dca631f
> Cr-Commit-Position: refs/heads/master@{#326560}

TBR=rmsousa@chromium.org,wez@chromium.org,dcaiafa@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=473758
Committed: https://crrev.com/da3ba0c9e7d2f0ae81f4d89097a6df56b3ec0df1
Cr-Commit-Position: refs/heads/master@{#326570}

[Sergey Ulanov, 2015-04-23 17:41:22]

Created Revert of Use standard ICE in Chromoting.

[commit-bot: I haz the power, 2015-04-23 17:42:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1089253005/1

[commit-bot: I haz the power, 2015-04-23 17:44:35]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-23 17:45:20]

Patchset 1 (id:??) landed as
https://crrev.com/da3ba0c9e7d2f0ae81f4d89097a6df56b3ec0df1
Cr-Commit-Position: refs/heads/master@{#326570}