Examine source code of Accessible Font Mode

{
  "name": "__MSG_extName__",
  "description": "__MSG_extDesc__",
  "version": "1.3.0",
  "manifest_version": 2,
  "browser_action": {
    "default_icon": {
      "16": "build/logo_16.png",
      "24": "build/logo_24.png",
      "32": "build/logo_32.png"
    },
    "default_popup": "build/popup.html"
  },
  "icons": {
    "16": "build/logo_16.png",
    "48": "build/logo_48.png",
    "128": "build/logo_128.png"
  },
  "web_accessible_resources": [
    "build/*"
  ],
  "background": {
    "scripts": [
      "build/browser-polyfill.js",
      "build/background_message.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "build/browser-polyfill.js",
        "build/content.js"
      ]
    }
  ],
  "permissions": [
    "tabs",
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{2c893d0c-2c21-32df-301c-91cf23cc73af}"
    }
  }
}