[cros] Captive portal dialog fixes.

[cros] Captive portal dialog fixes.

1. Add another handler showCaptivePortal that is used when user clicks on "visit network sign in page" on error screen.
This call will reload test page (generate_204) in a dialog and forces it to be shown i.e. does not wait till redirect will happen.

2. In case of flimflam portal state show dialog immediately (i.e. fix case when we're not detecting redirect properly). User might close/reload dialog manually if portal page won't load.

3. Disable "generate_204 loaded" check for now as it is not working correctly on networks with no connectivity (no DNS resolution for instance). Rely on flimflam portal check to close dialog when connection is fine.
Bonus: in case of limited connectivity dialog is not automatically closed so generic Chrome error page is shown which has useful information like DNS resolution failed etc.

BUG=chromium-os:28629
TEST=Manual. I've did testing with Coova captive portal, proxy settings, WiFi point with/without connectivity.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=129395

[Dmitry Polukhin, 2012-03-27 13:40:41]

LGTM with nit

https://chromiumcodereview.appspot.com/9861015/diff/2001/chrome/browser/chrom...
File chrome/browser/chromeos/login/captive_portal_view.cc (right):

https://chromiumcodereview.appspot.com/9861015/diff/2001/chrome/browser/chrom...
chrome/browser/chromeos/login/captive_portal_view.cc:296: /*if (!is_loading &&
!redirected_)
Please use C++ comments.

[Nikita (slow), 2012-03-27 14:01:36]

https://chromiumcodereview.appspot.com/9861015/diff/2001/chrome/browser/chrom...
File chrome/browser/chromeos/login/captive_portal_view.cc (right):

https://chromiumcodereview.appspot.com/9861015/diff/2001/chrome/browser/chrom...
chrome/browser/chromeos/login/captive_portal_view.cc:296: /*if (!is_loading &&
!redirected_)
On 2012/03/27 13:40:41, Dmitry Polukhin wrote:
> Please use C++ comments.

Done.

[commit-bot: I haz the power, 2012-03-27 15:21:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/nkostylev@chromium.org/9861015/7

[commit-bot: I haz the power, 2012-03-27 18:35:58]

Try job failure for 9861015-7 (retry) on win_rel for steps "browser_tests,
installer_util_unittests".
It's a second try, previously, steps "browser_tests, installer_util_unittests"
failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2012-03-27 20:31:28]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/nkostylev@chromium.org/9861015/7

[commit-bot: I haz the power, 2012-03-27 23:48:57]

Try job failure for 9861015-7 (retry) on win for step "compile" (clobber build).
It's a second try, previously, step "compile" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win&number...

[commit-bot: I haz the power, 2012-03-28 04:39:21]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/nkostylev@chromium.org/9861015/7

[commit-bot: I haz the power, 2012-03-28 12:30:48]

Change committed as 129395