Github tabsize switch

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Github tabsize switch",
  "version": "0.3.1",
  "description": "Customize tabsize (2/4/8) on Github.",
  "icons": {
    "128": "assets/tabsize-8.png"
  },
  "browser_action": {
    "default_title": "Click to switch tabsize on Github."
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "https://*/*"
      ],
      "include_globs": [
        "https://github.*",
        "https://*.github.*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end",
      "all_frames": true
    }
  ],
  "permissions": [
    "tabs",
    "activeTab",
    "storage"
  ]
}