UserAgent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3470.23 Safari/537.36

Steps to reproduce the problem:
1. Create a Chrome extension
2. In background script disable content security policy
3. In a content script execute an inline event at document start
4. In that inline event override `addEventListener` property of the `EventTarget` prototype with a proxified object
5. In the `apply` proxy trap call the debugger using `debugger` statement
6. Navigate to any webpage
7. Open Chrome DevTools
8. Press any button on that webpage

What is the expected behavior?
Expected behavior is to pause the debugger at `debugger` statement like in all other JavaScript files.

What went wrong?
Debugger is actually paused where it should be paused, but in the `Sources` tab of the DevTools, instead of displaying the script at which the debugger is paused, Chrome currently displays the html file of the webpage.

If the steps mentioned above seem confusing or unclear, I'm attaching here an example minimal extension and a webpage you can test the extension on. Notice, I tested this on Chrome 63.0.3239.132, I'm not sure if it reproduces in other versions.

Did this work before? N/A 

Chrome version: 63.0.3239.132  Channel: stable
OS Version: 6.3
Flash Version: /