Chrome Version       : 67.0.3396.87
OS Version: OS X 10.13.4

What steps will reproduce the problem?
See https://github.com/firebase/firebase-js-sdk/issues/939 for the external report against the Google Cloud Firestore SDK for web (which uses IndexedDb for persistence).  Per the reporter: this happen when laptop go to sleep and back again; NOT EVERY TIME.
according to screen-shot after laptop wakeup firestore will display error;
TimeoutError: Transaction timed out due to inactivity.

What is the expected result?
IndexedDb transaction timeouts should somehow coordinate with laptop sleep and avoid expiring without the browser / app having a chance to continue using the transaction.

What happens instead of that?
My hypothesis is that the laptop goes to sleep while the transaction is in-progress and the 30 second timer doesn't take into account that the laptop went to sleep and so the timer expires immediately after wake-up and the JS engine doesn't get a chance to use the transaction again.  Alternatively it's possible that the laptop is just "super slow" (swapping in memory, etc.) after wake-up that transactions are timing out.

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