Examine source code of Custom Popup Buttons

{
  "manifest_version": 2,
  "name": "Custom popup buttons",
  "version": "4.1resigned1",
  "permissions": [
    "storage",
    "tabs",
    "activeTab",
    "<all_urls>",
    "history",
    "downloads"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "dark.js",
        "dim.js"
      ],
      "run_at": "document_start",
      "match_about_blank": false,
      "all_frames": true
    }
  ],
  "browser_action": {
    "default_icon": "icons/Cpb-32.png",
    "default_title": "Custom popup buttons",
    "default_popup": "popup/Custom popup buttons.html",
    "browser_style": false
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icons/Cpb-48.png"
  },
  "applications": {
    "gecko": {
      "id": "dobrojutro@cpb.com"
    }
  }
}