manifest.json

{
    "manifest_version": 2,
    "name": "Messages for Web",
    "version": "0.1.1",
    "description": "Android Messages for Web implemented in a clean popup window, removing the browser clutter and letting you focus on the web app.",
    "content_scripts": [{
        "matches": [
            "<all_urls>"
        ],
        "js": ["content.js"]
    }],
    "permissions": ["declarativeContent", "tabs"],
    "background": {
        "scripts": ["background.js"],
        "persistent": false
    },
    "browser_action": {
        "default_icon": {
            "16": "assets/messages-icon-16.png",
            "32": "assets/messages-icon-32.png",
            "64": "assets/messages-icon-64.png",
            "128": "assets/messages-icon-128.png"
        }
    },
    "icons": {
        "16": "assets/messages-icon-16.png",
        "32": "assets/messages-icon-32.png",
        "64": "assets/messages-icon-64.png",
        "128": "assets/messages-icon-128.png"
    }
}