Examine source code of Fire Detector

{
  "name": "__MSG_extName__",
  "icons": {
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "short_name": "__MSG_extShortName__",
  "manifest_version": 2,
  "version": "1.0.2",
  "description": "__MSG_extDesc__",
  "default_locale": "en",
  "background": {
    "page": "background.html"
  },
  "page_action": {
    "default_icon": "icons/icon.png",
    "default_title": "__MSG_pageActionTitle__",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "js/main.js"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "webRequest",
    "http://*/*",
    "https://*/*"
  ],
  "web_accessible_resources": [
    "js/detector.js"
  ]
}