[IndexedDB] Fixing early destruction of connection during forceclose

Patch is as small as possible for merging.

Bug: 842990
Change-Id: I9968ffee1bf3279e61e1ec13e4d541f713caf12f
Reviewed-on: https://chromium-review.googlesource.com/1062935
Commit-Queue: Daniel Murphy <dmurph@chromium.org>
Commit-Queue: Victor Costan <pwnall@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#559383}
  OpenRequest(scoped_refptr<IndexedDBDatabase> db,
              std::unique_ptr<IndexedDBPendingConnection> pending_connection)
      : ConnectionRequest(db), pending_(std::move(pending_connection)) {}

  OpenRequest(scoped_refptr<IndexedDBDatabase> db,
              std::unique_ptr<IndexedDBPendingConnection> pending_connection)
      : ConnectionRequest(db), pending_(std::move(pending_connection)) {}
