Revert "feat(WebWorkers): Add WebWorker Todo Example. Add support for more DOM events."

This reverts commit d44827a4c5.

This broke master due to a race condition in our presubmit queue.

tools/broccoli/trees/browser_tree.ts

@@ -64,8 +64,7 @@ const kServedPaths = [
   'examples/src/material/radio',
   'examples/src/material/switcher',
   'examples/src/message_broker',
-  'examples/src/web_workers/kitchen_sink',
-  'examples/src/web_workers/todo'
+  'examples/src/web_workers'
 ];