Do not use the 'original' profile for guest sessions

Do not use the 'original' profile for guest sessions

For guest sessions (profile->IsGuestSession), we do not use
profile->GetOriginalProfile() for browser windows, we use the off the
record profile instead.

This was triggering an assert at the top of Browser::Browser().

BUG=434491
Committed: https://crrev.com/547026d2aff99e662d8dffe01b0ac1bfe81183d3
Cr-Commit-Position: refs/heads/master@{#305053}

[stevenjb, 2014-11-20 00:50:42]

stevenjb@chromium.org changed reviewers:
+ sky@chromium.org

[stevenjb, 2014-11-20 00:59:48]

stevenjb@chromium.org changed reviewers:
+ skuhne@chromium.org

[Mr4D (OOO till 08-26), 2014-11-20 04:19:37]

lgtm

[sky, 2014-11-20 15:07:01]

LGTM

[stevenjb, 2014-11-20 17:48:44]

The CQ bit was checked by stevenjb@chromium.org

[commit-bot: I haz the power, 2014-11-20 17:49:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/741883002/1

[commit-bot: I haz the power, 2014-11-20 18:59:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-11-20 19:00:27]

Patchset 1 (id:??) landed as
https://crrev.com/547026d2aff99e662d8dffe01b0ac1bfe81183d3
Cr-Commit-Position: refs/heads/master@{#305053}