message: Add logging to diagnose non-disappearing toasts
  For
diff: @@ -297,8 +297,9 @@ export default class DeviceListener {
  }
  }
  - logger.log("Old unverified sessions: " + Array.from(oldUnverifiedDeviceIds).join(','));
  - logger.log("New unverified sessions: " + Array.from(newUnverifiedDeviceIds).join(','));
  + logger.debug("Old unverified sessions: " + Array.from(oldUnverifiedDeviceIds).join(','));
  + logger.debug("New unverified sessions: " + Array.from(newUnverifiedDeviceIds).join(','));
  + logger.debug("Currently showing toasts for: " + Array.from(this.displayingToastsForDeviceIds).join(','));
  // Display or hide the batch toast for old unverified sessions
  if (oldUnverifiedDeviceIds.size > 0) {
  @@ -315,6 +316,7 @@ export default class DeviceListener {
  // ...and hide any we don't need any more
  for (const deviceId of this.displayingToastsForDeviceIds) {
  if (!newUnverifiedDeviceIds.has(deviceId)) {
  + logger.debug("Hiding unverified session toast for " + deviceId);
  hideUnverifiedSessionsToast(deviceId);
  }
  }
  