Revert of Roll src/third_party/libsrtp 6446144:f0957e8 (svn 292694:295151)

Revert of Roll src/third_party/libsrtp 6446144:f0957e8 (svn 292694:295151) (patchset #7 id:120001 of https://codereview.chromium.org/981593002/)

Reason for revert:
Broke the Windows GN bots (https://build.chromium.org/p/chromium.win/builders/Win8%20GN)

Original issue's description:
> Roll src/third_party/libsrtp 6446144:9c53f85 (svn 292694:295151)
>
> This updates libsrtp to 1.5.2 and uses the OpenSSL/BoringSSL crypto code.
> See https://codereview.chromium.org/889083003/ and https://codereview.chromium.org/1098043003/
>
> Summary of changes available at:
> https://chromium.googlesource.com/chromium/deps/libsrtp/+log/6446144..9c53f85
>
> BUG=328475
>
> Committed: https://crrev.com/94c5e80d3a385e223279b8ddb3ed8aa19d69a0e9
> Cr-Commit-Position: refs/heads/master@{#328972}

TBR=jiayl@chromium.org,juberti@chromium.org,thakis@chromium.org,mail@joachim-bauch.de
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=328475
Committed: https://crrev.com/f7c37d56082175b8b21e0c8cbdea72a7d8b3ea26
Cr-Commit-Position: refs/heads/master@{#328981}

[Garrett Casto, 2015-05-08 17:48:55]

Created Revert of Roll src/third_party/libsrtp 6446144:f0957e8 (svn
292694:295151)

[commit-bot: I haz the power, 2015-05-08 17:52:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1131323002/1

[commit-bot: I haz the power, 2015-05-08 17:56:01]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-08 17:58:17]

Patchset 1 (id:??) landed as
https://crrev.com/f7c37d56082175b8b21e0c8cbdea72a7d8b3ea26
Cr-Commit-Position: refs/heads/master@{#328981}