Release unique_ids_lock_ in Autofill PDM in case observers need to acquire it.
Release unique_ids_lock_ in Autofill PDM in case observers need to acquire it.

BUG=58426
TEST=none

Review URL: http://codereview.chromium.org/3549028

git-svn-id: http://src.chromium.org/svn/trunk/src@62049 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 32bcc88f04ec57c0eee6f496bba953dec19a5bf2
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser