[ChromeOS] Assorted WebUI login fixes.

[ChromeOS] Assorted WebUI login fixes.

- Respect account settings by using the users list and other flags passed into
  WebUILoginDisplay::Init;
- Limit max 5 users to avoid scrolling in account picker;
- Increase account picker width to 1100px to avoid crop on user pods;
- Properly remove a user, i.e. go through UserManager::RemoveUser instead
  of delete it directly using RemoveUserFromList;
- Improve the tab order;
- Switch to Gaia sign in if user failed login three times in a row;
- Turn off init animation;

BUG=chromium-os:18532, chromium-os:18668, chromium-os:18312, chromium-os:18307
TEST=Verify fix for chromium-os:18532,chromium-os:18668,chrmoum-os:18312 and chromium-os:18307.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=95551

[zel, 2011-08-05 00:01:48]

LGTM

http://codereview.chromium.org/7461142/diff/1/chrome/browser/resources/chrome...
File chrome/browser/resources/chromeos/login/screen_gaia_signin.js (right):

http://codereview.chromium.org/7461142/diff/1/chrome/browser/resources/chrome...
chrome/browser/resources/chromeos/login/screen_gaia_signin.js:53:
console.log('Opening extension: ' + JSON.stringify(data));
please make sure we have no private info of any sort dumped here

[xiyuan, 2011-08-05 01:04:12]

Done and submitting...

http://codereview.chromium.org/7461142/diff/1/chrome/browser/resources/chrome...
File chrome/browser/resources/chromeos/login/screen_gaia_signin.js (right):

http://codereview.chromium.org/7461142/diff/1/chrome/browser/resources/chrome...
chrome/browser/resources/chromeos/login/screen_gaia_signin.js:53:
console.log('Opening extension: ' + JSON.stringify(data));
On 2011/08/05 00:01:49, zel wrote:
> please make sure we have no private info of any sort dumped here

Done. Changed to just output startUrl and email property of data.