All current browsertests that test restoring kill the browser but keep the session. This doesn't actually test the session storage restore functionality.
See https://cs.chromium.org/chromium/src/chrome/browser/sessions/session_restore_browsertest.cc?q=session_restore_browsertest&dr&l=1396

We should create a PRE and post-test that does this, similar to the local storage one in dom_storage_browsertest.cc