Examine source code of Tab Statistics

{
  "name": "Tab Statistics",
  "description": "Statistics for tab count, opened, closed and switched for a given day.",
  "manifest_version": 2,
  "version": "2.0.3",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Tab statistics not yet initialized",
    "default_icon": {
      "16": "icon.png",
      "32": "icon.png",
      "48": "icon.png",
      "96": "icon.png"
    }
  },
  "permissions": [
    "downloads",
    "storage"
  ]
}