Firefox 57 "Quantum"
var controller = new AbortController()
var signal = controller.signal
downloadBtn.addEventListener('click', fetchVideo)
abortBtn.addEventListener('click', function() {
controller.abort()
console.log('Download aborted')
})
function fetchVideo() {
...
fetch(url, {signal}).then(function(response) {...}).catch(function(e) {
reports.textContent = 'Download error: ' + e.message
})
}
