CustomCSS Injector

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "CustomCSS Injector",
  "short_name": "CSS Injector",
  "version": "1.0",
  "description": "Write any CSS rules for any websites",
  "manifest_version": 2,
  "icons": {
    "48": "icons/CCSSI_icon_v2_48.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "<all_urls>",
    "contextMenus",
    "notifications"
  ],
  "browser_action": {
    "browser_style": true,
    "default_popup": "popup/popup.html",
    "default_icon": {
      "48": "icons/CCSSI_icon_v2_48.png",
      "96": "icons/CCSSI_icon_v2_96.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "customcss.js"
      ],
      "run_at": "document_start",
      "all_frames": true,
      "match_about_blank": true
    }
  ]
}