GitLab

IndexedDBDatabase requires BrowserThread::IO to be alive when it is
destroyed or it leaks some of its DeleteOnIOThread scoped_refptr members.
Not doing so results in LSAN failures in
https://codereview.chromium.org/2464233002 per it tightening
TestBrowserThread's shutdown semantics.

BUG=653916

Review-Url: https://codereview.chromium.org/2566693004
Cr-Commit-Position: refs/heads/master@{#437899}