ServiceWorker: Let dtor of SWRegistration work in the shutdown sequence

ServiceWorker: Let dtor of SWRegistration work in the shutdown sequence

Currently the destructor of SWRegistration just returns without any operations
during shutdown because DCHECK_CURRENTLY_ON(BrowserThread::IO) used not to work
when shutting down. This patch removes the early return because
DCHECK_CURRENTLY_ON is now working thanks to https://crrev.com/2180253003.
Once the dtor works, a pointer to SWRegistration owned by SWVersion::listeners_
will be removed appropreately.

Here is steps to repro:
1) Make a tab controlled by a service worker
2) Edit that service worker so the next update would install a new version.
3) Open another tab controlled by the service worker.
4) Now you should have an active worker and a waiting worker
5) Ctrl+Shift+Q to quit the browser. ServiceWorkerRegistration destructor will
   be called during shutdown.

BUG=658702
Committed: https://crrev.com/667f50ff47ad7217f21b80369dde3698e4c758c9
Cr-Commit-Position: refs/heads/master@{#429234}

[shimazu, 2016-11-02 05:17:04]

shimazu@chromium.org changed reviewers:
+ falken@chromium.org

[shimazu, 2016-11-02 05:17:04]

ptal

[shimazu, 2016-11-02 05:18:27]

The CQ bit was checked by shimazu@chromium.org to run a CQ dry run

[falken, 2016-11-02 05:18:28]

looks good, but Please add data to the CL description about why this is now OK
and how we verified it.

[commit-bot: I haz the power, 2016-11-02 05:18:38]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[shimazu, 2016-11-02 06:48:13]

Description was changed from

==========
ServiceWorker: Let dtor of SWRegistration work in the shutdown sequence

Currently the destructor of SWRegistration just returns without any
operations during shutdown. It might cause a dangling pointer owned by
SWVersion.

BUG=658702
==========

to

==========
ServiceWorker: Let dtor of SWRegistration work in the shutdown sequence

Currently the destructor of SWRegistration just returns without any operations
during shutdown because DCHECK_CURRENTLY_ON(BrowserThread::IO) used not to work
when shutting down. This patch removes the early return because
DCHECK_CURRENTLY_ON is now working thanks to https://crrev.com/2180253003.
Once the dtor works, a pointer to SWRegistration owned by SWVersion::listeners_
will be removed appropreately.

Here is steps to repro:
1) Make a tab controlled by a service worker
2) Edit that service worker so the next update would install a new version.
3) Open another tab controlled by the service worker.
4) Now you should have an active worker and a waiting worker
5) Ctrl+Shift+Q to quit the browser. ServiceWorkerRegistration destructor will
   be called during shutdown.

BUG=658702
==========

[commit-bot: I haz the power, 2016-11-02 07:00:11]

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

[commit-bot: I haz the power, 2016-11-02 07:00:12]

Dry run: This issue passed the CQ dry run.

[shimazu, 2016-11-02 07:24:18]

On 2016/11/02 05:18:28, falken wrote:
> looks good, but Please add data to the CL description about why this is now OK
> and how we verified it.

Thanks, updated.

[falken, 2016-11-02 07:40:03]

lgtm, thanks

[shimazu, 2016-11-02 07:48:39]

The CQ bit was checked by shimazu@chromium.org

[commit-bot: I haz the power, 2016-11-02 07:48:53]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-11-02 07:54:55]

Description was changed from

==========
ServiceWorker: Let dtor of SWRegistration work in the shutdown sequence

Currently the destructor of SWRegistration just returns without any operations
during shutdown because DCHECK_CURRENTLY_ON(BrowserThread::IO) used not to work
when shutting down. This patch removes the early return because
DCHECK_CURRENTLY_ON is now working thanks to https://crrev.com/2180253003.
Once the dtor works, a pointer to SWRegistration owned by SWVersion::listeners_
will be removed appropreately.

Here is steps to repro:
1) Make a tab controlled by a service worker
2) Edit that service worker so the next update would install a new version.
3) Open another tab controlled by the service worker.
4) Now you should have an active worker and a waiting worker
5) Ctrl+Shift+Q to quit the browser. ServiceWorkerRegistration destructor will
   be called during shutdown.

BUG=658702
==========

to

==========
ServiceWorker: Let dtor of SWRegistration work in the shutdown sequence

Currently the destructor of SWRegistration just returns without any operations
during shutdown because DCHECK_CURRENTLY_ON(BrowserThread::IO) used not to work
when shutting down. This patch removes the early return because
DCHECK_CURRENTLY_ON is now working thanks to https://crrev.com/2180253003.
Once the dtor works, a pointer to SWRegistration owned by SWVersion::listeners_
will be removed appropreately.

Here is steps to repro:
1) Make a tab controlled by a service worker
2) Edit that service worker so the next update would install a new version.
3) Open another tab controlled by the service worker.
4) Now you should have an active worker and a waiting worker
5) Ctrl+Shift+Q to quit the browser. ServiceWorkerRegistration destructor will
   be called during shutdown.

BUG=658702
==========

[commit-bot: I haz the power, 2016-11-02 07:54:56]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-02 07:59:29]

Description was changed from

==========
ServiceWorker: Let dtor of SWRegistration work in the shutdown sequence

Currently the destructor of SWRegistration just returns without any operations
during shutdown because DCHECK_CURRENTLY_ON(BrowserThread::IO) used not to work
when shutting down. This patch removes the early return because
DCHECK_CURRENTLY_ON is now working thanks to https://crrev.com/2180253003.
Once the dtor works, a pointer to SWRegistration owned by SWVersion::listeners_
will be removed appropreately.

Here is steps to repro:
1) Make a tab controlled by a service worker
2) Edit that service worker so the next update would install a new version.
3) Open another tab controlled by the service worker.
4) Now you should have an active worker and a waiting worker
5) Ctrl+Shift+Q to quit the browser. ServiceWorkerRegistration destructor will
   be called during shutdown.

BUG=658702
==========

to

==========
ServiceWorker: Let dtor of SWRegistration work in the shutdown sequence

Currently the destructor of SWRegistration just returns without any operations
during shutdown because DCHECK_CURRENTLY_ON(BrowserThread::IO) used not to work
when shutting down. This patch removes the early return because
DCHECK_CURRENTLY_ON is now working thanks to https://crrev.com/2180253003.
Once the dtor works, a pointer to SWRegistration owned by SWVersion::listeners_
will be removed appropreately.

Here is steps to repro:
1) Make a tab controlled by a service worker
2) Edit that service worker so the next update would install a new version.
3) Open another tab controlled by the service worker.
4) Now you should have an active worker and a waiting worker
5) Ctrl+Shift+Q to quit the browser. ServiceWorkerRegistration destructor will
   be called during shutdown.

BUG=658702

Committed: https://crrev.com/667f50ff47ad7217f21b80369dde3698e4c758c9
Cr-Commit-Position: refs/heads/master@{#429234}
==========

[commit-bot: I haz the power, 2016-11-02 07:59:31]

Patchset 1 (id:??) landed as
https://crrev.com/667f50ff47ad7217f21b80369dde3698e4c758c9
Cr-Commit-Position: refs/heads/master@{#429234}