Add additional CHECKs to AppListModel.

Add additional CHECKs to AppListModel.

I can't determine why we are seeing crashes in 	AppListItemList::AddItem
from inspection, so I am adding some more rigorous CHECKs in Release to
help track down the root cause. This shouldn't make the code crash more
often, just sooner and hopefully someplace where we can identify the
problem.

BUG=402357
Committed: https://crrev.com/4d065e13362ff1c0ee18224c15cb1d8d5e82db41
Cr-Commit-Position: refs/heads/master@{#291939}

[stevenjb, 2014-08-19 20:43:04]

tapted@, benwells@, can one of you test this on Windows and make sure it doesn't
generate a reproducible crash? I won't have access to a Windows machine for a
while. I'm not seeing any new crashes on Linux / ChromeOS, but we are only
seeing the shutdown crash on Windows.

[stevenjb, 2014-08-22 16:57:47]

ping?

[benwells, 2014-08-24 23:06:39]

I'll defer this review to tapted

[tapted, 2014-08-25 04:25:45]

lgtm - just a few nits.

Sorry for the review lag. I got my Windows build up to speed, patched this and
did some spot checks. Didn't coax out any crashes.

Just FYI - I'm tracking some obscure AppList crashes in http://crbug.com/405827
http://crbug.com/373689 . A change I have in
https://codereview.chromium.org/492163002/ might sort some of those out, but I
don't think there's an obvious link to the issue here.

https://codereview.chromium.org/487853003/diff/20001/ui/app_list/app_list_mod...
File ui/app_list/app_list_model.cc (right):

https://codereview.chromium.org/487853003/diff/20001/ui/app_list/app_list_mod...
ui/app_list/app_list_model.cc:77: CHECK(item->folder_id() != folder_id);
nit: CHECK_NE?

https://codereview.chromium.org/487853003/diff/20001/ui/app_list/app_list_mod...
ui/app_list/app_list_model.cc:163: CHECK(item->folder_id().empty());
nit: CHECK(!item->IsInFolder()) - may be marginally more readable/understandable
in a log

https://codereview.chromium.org/487853003/diff/20001/ui/app_list/app_list_mod...
ui/app_list/app_list_model.cc:362: CHECK(item_ptr->folder_id() != folder->id());
nit: CHECK_NE?

[stevenjb, 2014-08-25 20:39:06]

No worries, thanks for checking this on Windows.

https://codereview.chromium.org/487853003/diff/20001/ui/app_list/app_list_mod...
File ui/app_list/app_list_model.cc (right):

https://codereview.chromium.org/487853003/diff/20001/ui/app_list/app_list_mod...
ui/app_list/app_list_model.cc:77: CHECK(item->folder_id() != folder_id);
On 2014/08/25 04:25:45, tapted wrote:
> nit: CHECK_NE?

Done.

https://codereview.chromium.org/487853003/diff/20001/ui/app_list/app_list_mod...
ui/app_list/app_list_model.cc:163: CHECK(item->folder_id().empty());
On 2014/08/25 04:25:45, tapted wrote:
> nit: CHECK(!item->IsInFolder()) - may be marginally more
readable/understandable
> in a log

Done.

https://codereview.chromium.org/487853003/diff/20001/ui/app_list/app_list_mod...
ui/app_list/app_list_model.cc:362: CHECK(item_ptr->folder_id() != folder->id());
On 2014/08/25 04:25:45, tapted wrote:
> nit: CHECK_NE?

Done.

[stevenjb, 2014-08-25 20:39:13]

The CQ bit was checked by stevenjb@chromium.org

[commit-bot: I haz the power, 2014-08-25 20:39:36]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/stevenjb@chromium.org/487853003/40001

[commit-bot: I haz the power, 2014-08-25 21:51:00]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  mac_chromium_rel_swarming on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[commit-bot: I haz the power, 2014-08-25 22:04:32]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-08-25 22:04:33]

Try jobs failed on following builders:
  mac_chromium_rel_swarming on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[stevenjb, 2014-08-26 16:53:29]

The CQ bit was checked by stevenjb@chromium.org

[commit-bot: I haz the power, 2014-08-26 16:54:24]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/stevenjb@chromium.org/487853003/40001

[commit-bot: I haz the power, 2014-08-26 17:30:47]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  mac_chromium_rel_swarming on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[commit-bot: I haz the power, 2014-08-26 18:09:53]

Committed patchset #3 (40001) as 1abc1a7f86dbad3ef44c3d0116c875ab92d293d3

[commit-bot: I haz the power, 2014-09-10 02:44:01]

Patchset 3 (id:??) landed as
https://crrev.com/4d065e13362ff1c0ee18224c15cb1d8d5e82db41
Cr-Commit-Position: refs/heads/master@{#291939}