Worklet: Remove outdated comment from WPT

Worklets don't support dynamic import (see the issue)

Bug: 782538
Change-Id: Iea9b4352122e78d1ff671ae09a9947f6a7f1ef3b
TBR: nhiroki@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/1058883Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558638}

third_party/WebKit/LayoutTests/external/wpt/worklets/resources/service-worker-interception-tests.js

@@ -120,6 +120,4 @@ function runServiceWorkerInterceptionTests(worklet_type) {
             })
           .then(msg_event => assert_equals(msg_event.data, 'RESOLVED'));
     }, 'Static import should be intercepted by a service worker.');
-
-    // TODO(nhiroki): Add tests for dynamic import.
 }