Crossbench Proxy extension: Custom replay button in DevTools > Recorder

This extension is using the chrome.devtools.recorder API.

To test the extension:

1. Download this directory to your machine: git clone https://chromium.googlesource.com/crossbench.
2. Load the extension locally.
3. Open a new tab and a new DevTools window.
4. In the Recorder panel, create a new recording.
5. Expand the replay menu and press crossbench.