Import w3c tests for the service workers

third_party/WebKit/LayoutTests/imported/wpt/service-workers/service-worker/resources/mint-new-worker.py

+import time
+
+body = '''
+onactivate = (e) => e.waitUntil(clients.claim());
+var resolve_wait_until;
+var wait_until = new Promise(resolve => {
+    resolve_wait_until = resolve;
+  });
+onmessage = (e) => {
+    if (e.data == 'wait')
+      e.waitUntil(wait_until);
+    if (e.data == 'go')
+      resolve_wait_until();
+  };'''
+
+def main(request, response):
+    headers = [('Cache-Control', 'no-cache, must-revalidate'),
+               ('Pragma', 'no-cache'),
+               ('Content-Type', 'application/javascript')]
+
+    skipWaiting = ''
+    if 'skip-waiting' in request.GET:
+      skipWaiting = 'skipWaiting();'
+
+    return headers, '/* %s %s */ %s %s' % (time.time(), time.clock(), skipWaiting, body)