To Fix Brave Bug for YouTube Live Chat
This is to fix the bug for Brave. (YouTube Live Chat)
Target User: Brave
See https://community.brave.com/t/youtube-live-chat-30-sec-delay/
YouTube calls "urlChanged" twice to set the iframe url.
In the first attempt, chatframe.contentDocument is null. So it will set the src of the iframe.
In the second attempt, chatframe.contentDocument is non-null. So it will set the url using chatframe.contentDocument.location.replace
Both Brave and Chrome will do these two attempts. Both attempts are just 10ms aparted.
The difference is, in brave, the first attempt affected the second attempt, but in chrome, the first attempt would not affect the second attempt.
