Verify that the current version of IndexedDB can read an IndexedDB
instance created by a previous version of Chrome stable.

These DBs were created with Chrome stable version 70.0.3538.77
(Official Build) (64-bit) on Linux.  The webapp used to create the
instances was provided in https://crbug.com/899446 by Victor Costan
<pwnall@chromium.org>.  The noai version is modified from that case
to disable autoincrement.

Bug: 717812
Bug: 899446
Change-Id: I0b293f68cde4d637c53faaabd52b3b27a0ac147c
Reviewed-on: https://chromium-review.googlesource.com/c/1320693Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Commit-Queue: Chase Phillips <cmp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605908}