Chrome

Modifying a Chrome App icon

Convert your image to a .icns. image2icon (brew cask install image2icon) is good and can work with images of any dimensions.
Copy your .icns file to ~/Applications/Chrome\ Apps.localized/$APP_NAME/Contents/Resources/app.icns
Refresh the icon cache: touch ~/Applications/Chrome\ Apps.localized/$APP_NAME
Restart the Dock: sudo killall Dock

Deleting a url suggestion from the autocomplete bar

Select the suggestion
On a Macbook Pro laptop keyboard: shift - fn - delete
On an Apple keyboard: shift - delete x

NB: you can't delete suggestions that are bookmarks. Remove the bookmark instead.

Inspecting shared workers

Visit chrome://inspect/#workers
Click inspect on the worker
Devtools will appear with the worker's console log

You can now navigate to the worker source and place breakpoints.