Fix WebRTC roll script.

Fix WebRTC roll script.
This is just replacing roll_dep with roll_dep_svn after the script was recently renamed.

Committed: https://crrev.com/6c356832979b97fd1fb07ca243029ca03fec60f8
Cr-Commit-Position: refs/heads/master@{#331287}

[tommi (sloooow) - chröme, 2015-05-25 11:21:06]

tommi@chromium.org changed reviewers:
+ phoglund@chromium.org
- maruel@chromium.org

[tommi (sloooow) - chröme, 2015-05-25 12:04:00]

tommi@chromium.org changed reviewers:
+ kjellander@chromium.org
- phoglund@chromium.org

[kjellander_chromium, 2015-05-25 12:12:49]

lgtm to unblock roll, but we should look into using the new script instead,
since we're no longer using svn.

[phoglund_chromium, 2015-05-25 12:28:26]

phoglund@chromium.org changed reviewers:
+ phoglund@chromium.org

[phoglund_chromium, 2015-05-25 12:28:26]

lgtm

[tommi (sloooow) - chröme, 2015-05-25 15:15:52]

The CQ bit was checked by tommi@chromium.org

[commit-bot: I haz the power, 2015-05-25 15:16:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1160523002/1

[commit-bot: I haz the power, 2015-05-25 15:21:09]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-25 15:22:05]

Patchset 1 (id:??) landed as
https://crrev.com/6c356832979b97fd1fb07ca243029ca03fec60f8
Cr-Commit-Position: refs/heads/master@{#331287}