[QuicTransport] Add wpt for constructor

Verify that the QuicTransport constructor rejects incorrect URLs.

Also verify that attempting to connect to port 0 fails.

BUG=1011392

Change-Id: I57d209569633c351dd408cdced1d7e44f92f1065
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2217680Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#773048}

third_party/blink/web_tests/external/wpt/webtransport/quic/constructor.any.js

+// META: global=window,worker
+// META: script=/common/get-host-info.sub.js
+
+const HOST = get_host_info().ORIGINAL_HOST;
+
+const BAD_URLS = [
+  null,
+  '',
+  'no-scheme',
+  'https://example.com/' /* scheme is wrong */,
+  'quic-transport:///' /* no host  specified */,
+  'quic-transport://example.com/#failing' /* has fragment */,
+  `quic-transport://${HOST}:999999/` /* invalid port */,
+];
+
+for (const url of BAD_URLS) {
+  test(() => {
+    assert_throws_dom('SyntaxError', () => new QuicTransport(url),
+                      'constructor should throw');
+  }, `QuicTransport constructor should reject URL '${url}'`);
+}
+
+// TODO(ricea): Test CSP.
+
+promise_test(t => {
+  const qt = new QuicTransport(`quic-transport://${HOST}:0/`);
+  return Promise.all([
+    promise_rejects_js(t, TypeError, qt.ready, 'ready promise rejects'),
+    promise_rejects_js(t, TypeError, qt.closed, 'closed promise rejects'),
+  ]);
+}, 'connection to port 0 should fail');