Examine source code of Full Tab

{
  "manifest_version": 2,
  "name": "Full Tab",
  "version": "1.8.0",
  "description": "Pixel-precise full-tab video. Right-click the icon to toggle Fit (contain/cover). Remembers your choice.",
  "permissions": [
    "activeTab",
    "storage",
    "contextMenus",
    "<all_urls>"
  ],
  "browser_action": {
    "default_title": "Video Full Tab (toggle)"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "video-full-tab@rob-bowman"
    }
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "64": "icons/icon-64.png",
    "128": "icons/icon-128.png"
  }
}