PLEASE NOTE: Due to a bug in polyserve and circular dependencies, this demo
is not running with the local version of iron-location, but rather whatever
is being served from /node_modules/@polymer/iron-location.
URL
Dwell Time
iron-location won't add extraneous entries to the browser's history
when changes come in quick succession.
A new history entry will only be added if iron-location stays in
the same state longer than dwellTime.