Examine source code of Empty Cache Button

{
  "manifest_version" : 2 ,
  "name" : "Empty Cache Button",
  "description" : "Cache clearing made easy. One click.",
  "version" : "3.5resigned1",
  "author": "mvm",
  "icons" : {
    "16" : "icons/16.png",
    "19" : "icons/19.png",
    "32" : "icons/32.png",
    "38" : "icons/38.png",
    "48" : "icons/48.png",
    "96" : "icons/96.png"
  },
  "browser_action" : {
    "default_title" : "Empty Cache",
    "default_icon" : {
      "16" : "icons/16.png",
      "19" : "icons/19.png",
      "32" : "icons/32.png",
      "38" : "icons/38.png",
      "48" : "icons/48.png",
      "96" : "icons/96.png"
    }
  },
  "options_ui" : {
    "page": "options/index.html" ,
    "browser_style": true
  },
  "background" : {
    "scripts" : [
      "background.js" 
    ]
  },
  "commands" : {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "F9"
      }
    }
  },
  "permissions" : [
    "notifications" ,
    "browsingData" ,
    "storage" 
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4cc4a13b-94a6-7568-370d-5f9de54a9c7f}"
    }
  }
}