Examine source code of Adjust Screen Color

{
  "background": {
    "persistent": true,
    "scripts": [
      "background.js",
      "data/tracker.js"
    ]
  },
  "browser_action": {
    "default_popup": "data/popup/index.html"
  },
  "commands": {
    "decrease": {
      "description": "Decrement brightness level by 0.05"
    },
    "increase": {
      "description": "Increment brightness level by 0.05"
    }
  },
  "content_scripts": [
    {
      "js": [
        "data/content.js"
      ],
      "matches": [
        "http://*/*",
        "https://*/*"
      ]
    }
  ],
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
  "default_locale": "en",
  "description": "__MSG_description__",
  "icons": {
    "16": "data/icons/16.png",
    "32": "data/icons/32.png",
    "48": "data/icons/48.png",
    "64": "data/icons/64.png",
    "128": "data/icons/128.png",
    "256": "data/icons/256.png",
    "512": "data/icons/512.png"
  },
  "manifest_version": 2,
  "name": "Adjust Screen Brightness",
  "options_ui": {
    "chrome_style": true,
    "page": "data/options/index.html"
  },
  "permissions": [
    "webNavigation",
    "storage",
    "alarms",
    "tabs",
    "idle",
    "<all_urls>",
    "webRequestBlocking",
    "webRequest"
  ],
  "version": "0.1.2",
  "browser_specific_settings": {
    "gecko": {
      "id": "{9fdd0c0e-b4f5-4d79-a0d6-1488dc35da5c}"
    }
  }
}