Examine source code of Autofill Email address

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "description": "__MSG_extensionDescription__",
  "default_locale": "ja",
  "version": "0.0.5",
  "permissions": [
    "tabs",
    "activeTab",
    "storage",
    "contextMenus"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "32": "icons/32.png",
    "64": "icons/64.png",
    "128": "icons/128.png"
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "applications": {
    "gecko": {
      "id": "autofill-email@nahi-da.com"
    }
  }
}