Add release assertion to ensure m_owningPointerForClose is null in UniqueIDBDatabase::invokeOperationAndTransactionTimer()

[Sihui Liu]

As in rdar://problem/44902833, RELEASE_ASSERT(!m_owningPointerForClose) in UniqueIDBDatabase::scheduleShutdownForClose() frequently gets hit, which means m_owningPointerForClose is already acquired for close and we should not reach scheduleShutdownForClose. 
Since scheduleShutdownForClose() is fired on timer, it's hard to tell which function dispatches it a second time from the crash log.

The added release assertions in the invoke function should help reveal the probblematic code path.

[Sihui Liu]

Created attachment 351325 [details]
Patch

[Chris Dumez]

Comment on attachment 351325 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=351325&action=review

> Source/WebCore/ChangeLog:8
> +        This would help debug rdar://problem/44902833.

How? I do not think we report to the user Network process crashes so they are unlikely to file a radar with reproduction case (since they won't know about the crash).

[Chris Dumez]

Comment on attachment 351325 [details]
Patch

Never mind. Getting the automated crash reports will suffice.

[WebKit Commit Bot]

Comment on attachment 351325 [details]
Patch

Clearing flags on attachment: 351325

Committed r236747: <https://trac.webkit.org/changeset/236747>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/44941165>