AppList shouldn't be dismissed when an app is uninstalled

AppList shouldn't be dismissed when an app is uninstalled

When an app is being uninstalled and the "confirm removal" dialog is
closed, the focus controller selects the most recently used window to
return focus to. However, the MruWindowTracker doesn't take into
consideration the app list container, and hence the app list window is
not on the MRU window list. Focus is then returned to something else (if
you have other windows open) which causes the dismissal of the App list.

R=oshima@chromium.org,skuhne@chromium.org
BUG=467877
Committed: https://crrev.com/bff9c2f7564000c3b912e18d70780d1a6263680f
Cr-Commit-Position: refs/heads/master@{#321276}

[afakhry, 2015-03-18 21:41:12]

afakhry@chromium.org changed reviewers:
+ skuhne@chromium.org

[afakhry, 2015-03-18 21:47:53]

@Oshima: Can you please review 'switchable_windows.cc'?
@Skuhne: Can you please review 'shelf_layout_manager_unittest.cc'? As per
Kuscher@, this is the expected consistent behavior to unhide the shelf when app
list is shown.

[Mr4D (OOO till 08-26), 2015-03-18 22:46:54]

lgtm for unit test

[oshima, 2015-03-18 22:49:00]

lgtm

[afakhry, 2015-03-19 00:54:25]

The CQ bit was checked by afakhry@chromium.org

[commit-bot: I haz the power, 2015-03-19 00:54:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1011283004/1

[commit-bot: I haz the power, 2015-03-19 02:43:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-19 02:44:00]

Patchset 1 (id:??) landed as
https://crrev.com/bff9c2f7564000c3b912e18d70780d1a6263680f
Cr-Commit-Position: refs/heads/master@{#321276}