kiosk: Close on the last window of kiosk app.

kiosk: Close on the last window of kiosk app.

Helper extension/app could have hidden windows created. Kiosk
app session should only be bound with the kiosk app's window and
not affected by them.

BUG=449313
Committed: https://crrev.com/7538ed2a80a3ecbb66527957a2cf2a4af75e3e99
Cr-Commit-Position: refs/heads/master@{#312980}

[xiyuan, 2015-01-23 23:57:33]

xiyuan@chromium.org changed reviewers:
+ jennyz@chromium.org

[jennyz, 2015-01-24 00:04:06]

lgtm

[xiyuan, 2015-01-24 00:05:39]

The CQ bit was checked by xiyuan@chromium.org

[commit-bot: I haz the power, 2015-01-24 00:06:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/873873002/1

[commit-bot: I haz the power, 2015-01-24 00:41:19]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-24 00:42:16]

Patchset 1 (id:??) landed as
https://crrev.com/7538ed2a80a3ecbb66527957a2cf2a4af75e3e99
Cr-Commit-Position: refs/heads/master@{#312980}

[bartfab (slow), 2015-01-26 15:59:46]

bartfab@chromium.org changed reviewers:
+ bartfab@chromium.org

[bartfab (slow), 2015-01-26 15:59:46]

What is a helper extension/app? How can there be more than one app active in a
single-app session?

https://codereview.chromium.org/873873002/diff/1/chrome/browser/chromeos/app_...
File chrome/browser/chromeos/app_mode/app_session_lifetime.cc (right):

https://codereview.chromium.org/873873002/diff/1/chrome/browser/chromeos/app_...
chrome/browser/chromeos/app_mode/app_session_lifetime.cc:76: std::string
app_id_;
Nit: const.

[xiyuan, 2015-01-26 17:21:32]

When I saw the problem, the windows are hidden IME windows. It looks like we
changed the IME window from native code into an app and caused this regression.

We allow some helper apps such as file manager to be used in kiosk session now.
So only looking at the main kiosk app's window is more correct.

https://codereview.chromium.org/873873002/diff/1/chrome/browser/chromeos/app_...
File chrome/browser/chromeos/app_mode/app_session_lifetime.cc (right):

https://codereview.chromium.org/873873002/diff/1/chrome/browser/chromeos/app_...
chrome/browser/chromeos/app_mode/app_session_lifetime.cc:76: std::string
app_id_;
On 2015/01/26 15:59:46, bartfab wrote:
> Nit: const.

Cannot use const here because we use it as a AppWindowHandler and app is is set
via an Init call instead of constructor.