login: Turn on verbose screen-locking logging in Chrome.
login: Turn on verbose screen-locking logging in Chrome.

BUG=chromium-os:155403
TEST=manual: checked that chrome's log has expected detail

Change-Id: I0208f19cc79d064d993f5802723041104124aec9
Reviewed-on: https://gerrit.chromium.org/gerrit/35337
Tested-by: Daniel Erat <69d56254d3d393520d06e9838c23c147a5fee7d9@chromium.org>
Reviewed-by: James Cook <3741fd56a17d4d5fef7af0902a2401859b0cd435@chromium.org>
Commit-Ready: Daniel Erat <69d56254d3d393520d06e9838c23c147a5fee7d9@chromium.org>

chadversary/chromiumos.platform.login_manager,chadversary/chromiumos.platform.login_manager,chadversary/chromiumos.platform.login_manager