Examine source code of Password Manager

{
  "manifest_version": 2,
  "default_locale": "en",
  "name": "__MSG_ext_name__",
  "author": "F-Secure",
  "short_name": "__MSG_ext_name_short__",
  "description": "__MSG_ext_description__",
  "version": "6.3.4",
  "icons": {
    "16": "img/ic_plugin_16.png",
    "48": "img/ic_plugin_48.png",
    "128": "img/ic_plugin_128.png"
  },
  "permissions": [
    "storage",
    "tabs",
    "nativeMessaging",
    "http://localhost/*"
  ],
  "browser_action": {
    "default_icon": "img/ic_plugin_off.png",
    "default_popup": "popups/notRunning.html",
    "default_title": "Password Manager by F-Secure",
    "browser_style": false
  },
  "background": {
    "scripts": [
      "shared.js",
      "config.js",
      "fskeyUtils.js",
      "customization.js",
      "ext/sjcl.js",
      "messaging.js",
      "serviceworker.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "ext/jquery.js",
        "config.js",
        "fskeyUtils.js",
        "customization.js",
        "ext/sjcl.js",
        "pagemngr.js",
        "loginhandler.js",
        "savecredentials.js",
        "content.js"
      ],
      "css": [
        "images.css",
        "fskey-base.css",
        "fskey-save-credentials.css"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ],
  "web_accessible_resources": [
    "img/*",
    "images.css",
    "fskey-base.css",
    "fskey-frame.css"
  ],
  "applications": {
    "gecko": {
      "id": "password-manager@f-secure.com",
      "strict_min_version": "58.0"
    }
  }
}