I had an issue with adding SVG icons for my addon button. According to the documentation, I should be able to add:
"browser_action": {
"default_icon": "/content/images/icon.svg",
…
}
but it doesn’t seem to work. Instead I use:
"browser_action": {
"default_icon": {
"24": "/content/images/icon.svg",
"48": "/content/images/icon.svg",
"96": "/content/images/icon.svg"
},
…
}
which does work.