Examine source code of Content Core

{
  "manifest_version": 2,
  "name": "Content Core",
  "version": "0.11",
  "description": "Desc",
  "icons": {
    "48": "icons/favicon.png",
    "96": "icons/favicon.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "browser-polyfill.min.js",
        "main.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "browser-polyfill.min.js",
      "background.js"
    ]
  },
  "permissions": [
    "<all_urls>",
    "tabs",
    "activeTab"
  ],
  "browser_action": {
    "default_popup": "popup.html"
  }
}