Examine source code of MobiDevTools

{
  "manifest_version" : 2 ,
  "name" : "MobiDevTools",
  "version" : "3.7",
  "description" : "DevTools-grade mobile developer console — free & open",
  "author": "Francesco De Stefano",
  "default_locale" : "en" ,
  "permissions" : [
    "tabs" ,
    "webRequest" ,
    "webNavigation" ,
    "<all_urls>" 
  ],
  "background" : {
    "scripts" : [
      "background.js" 
    ],
    "persistent" : true 
  },
  "browser_action" : {
    "default_icon" : {
      "16" : "icons/icon16.png",
      "32" : "icons/icon32.png",
      "48" : "icons/icon48.png"
    },
    "default_title" : "MobiDevTools"
  },
  "icons" : {
    "16" : "icons/icon16.png",
    "32" : "icons/icon32.png",
    "48" : "icons/icon48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "@mobidevtools",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_security_policy" : "script-src 'self'; object-src 'self'; style-src 'self' 'unsafe-inline'; font-src 'self' data:; img-src 'self' data: blob:; default-src 'self' data: blob:;"
}