Worker: Modernize dedicated-worker-options-type.html using assert_throws

This CL is for code cleanup.
This doesn't change the behavior.

Bug: n/a
Change-Id: Iac4a44781fde183881cea62a97c8883932a670ac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2011593
Commit-Queue: Eriko Kurimoto <elkurin@google.com>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734341}

third_party/blink/web_tests/external/wpt/workers/modules/dedicated-worker-options-type.html

@@ -25,23 +25,22 @@ promise_test(() => {
 }, 'Test worker construction with the "module" worker type.');
 
 test(() => {
-  try {
-    new Worker('resources/post-message-on-load-worker.js', { type: '' });
-    assert_unreached(
-        'Worker construction with an empty type should throw an exception');
-  } catch (e) {
-    assert_equals(e.name, 'TypeError');
-  }
+  assert_throws(
+      new TypeError(),
+      () => {
+        new Worker('resources/post-message-on-load-worker.js', { type: '' });
+      },
+      'Worker construction with an empty type should throw an exception');
 }, 'Test worker construction with an empty worker type.');
 
 test(() => {
-  try {
-    new Worker('resources/post-message-on-load-worker.js', { type: 'unknown' });
-    assert_unreached(
-        'Worker construction with an unknown type should throw an exception');
-  } catch (e) {
-    assert_equals(e.name, 'TypeError');
-  }
+  assert_throws(
+      new TypeError(),
+      () => {
+        new Worker('resources/post-message-on-load-worker.js',
+                   { type: 'unknown' });
+      },
+      'Worker construction with an unknown type should throw an exception');
 }, 'Test worker construction with an unknown worker type.');
 
 </script>