Scripts to use chrome as a login manager

Scripts to use chrome as a login manager.

These are still prototypes, and without the right version of chrome will not work yet.

When this code is active, the fundamental changes are as follows:

1) slim is no longer used
2) $HOME is now /home/chronos/user
3) Chrom[e|ium]'s --user-data-dir=/home/chronos
4) Chrom[e|ium]'s --profile=/home/chronos/user
5) We no longer have a way to specify a set of tabs to open the FIRST TIME a user logs in.  Session restore still works.
6) login time is reduced, as we no longer need to wait to start Chrome until _after_ the user authenticates

Temporary regressions:
1) Chrome tracks opting-in to stats collection on a per-user-data-dir level.  Until this is per-profile, we can only opt into stats collection on a per-machine basis.  As such, this disables stats collection when chrome is used as the login manager
2) The login manager window has normal window manager decorations on it, and can be dismissed by clicking on the close box.  This needs to be addressed in the browser.

[sosa, 2009-12-09 23:03:12]

lgtm besides a few nits

http://codereview.chromium.org/479011/diff/1/7
File start_login.sh (right):

http://codereview.chromium.org/479011/diff/1/7#newcode18
start_login.sh:18: mkdir -p ${HOME}
Do we really have to -p this?

http://codereview.chromium.org/479011/diff/1/7#newcode20
start_login.sh:20: exec /usr/bin/chromeos-chrome-login 2>> /tmp/login_mgr.log
May we want this to persist for debugging purposes?  Isn't /tmp on tmpfs

http://codereview.chromium.org/479011/diff/1/8
File start_wm.sh (right):

http://codereview.chromium.org/479011/diff/1/8#newcode4
start_wm.sh:4: # It runs sensible-browser, which uses $BROWSER.
These comments do not make sense to me.

[Chris Masone, 2009-12-10 00:31:55]

http://codereview.chromium.org/479011/diff/1/7
File start_login.sh (right):

http://codereview.chromium.org/479011/diff/1/7#newcode18
start_login.sh:18: mkdir -p ${HOME}
On 2009/12/09 23:03:12, sosa wrote:
> Do we really have to -p this?

is there any reason not to?  We might wind up moving it around at some point.

http://codereview.chromium.org/479011/diff/1/7#newcode20
start_login.sh:20: exec /usr/bin/chromeos-chrome-login 2>> /tmp/login_mgr.log
On 2009/12/09 23:03:12, sosa wrote:
> May we want this to persist for debugging purposes?  Isn't /tmp on tmpfs

yup, moved this as we discussed

http://codereview.chromium.org/479011/diff/1/8
File start_wm.sh (right):

http://codereview.chromium.org/479011/diff/1/8#newcode4
start_wm.sh:4: # It runs sensible-browser, which uses $BROWSER.
On 2009/12/09 23:03:12, sosa wrote:
> These comments do not make sense to me.  

I moved this to where it needs to be.  It has to do with how the system decides
how to open files.

[sosa, 2009-12-10 00:34:51]

lgtm!