Why Is Chrome.runtime Undefined In The Content Script?

I have a very simple chrome extension, where I'm trying to pass a message from the background script to the content script. But chrome.runtime is undefined. Here's literally all t

Solution 1:

Ok I figured it out. It's absolutely stupid, but it appears this is simply a Heisenbug. By adding a breakpoint, or debugger statement, it causes that value to be undefined. Maybe a chrome bug?

I swear, every day Chrome feels more, and more like Internet Explorer.