Examine source code of Tab Task - Google Task

{
  "manifest_version": 2,
  "name": "Tab Task",
  "version": "1.1",
  "description": "Create a Google Task with a link to the active tab",
  "icons": {
    "512": "icons/icon.png"
  },
  "browser_action": {
    "default_icon": "icons/icon.png",
    "default_title": "Add to Tasks",
    "default_popup": "popup/add.html"
  },
  "permissions": [
    "storage",
    "identity",
    "tabs"
  ],
  "options_ui": {
    "page": "options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e6e80512-76a6-4289-a2c8-78209547c375}"
    }
  }
}