login: Get rid of Chrome log file rotation.
login: Get rid of Chrome log file rotation.

A separate change makes us just store all of the log
files in /var/log/chrome instead.

BUG=none
TEST=tried it

Review URL: http://codereview.chromium.org/3170046

Change-Id: Ib254422b36bda655b44994f8912e45368c45e45c

joshfire/chromiumos-platform-login_manager,chadversary/chromiumos.platform.login_manager,joshfire/chromiumos-platform-login_manager,chadversary/chromiumos.platform.login_manager,joshfire/chromiumos-platform-login_manager,chadversary/chromiumos.platform.login_manager