Examine source code of Copy page url

{
  "manifest_version": 2,
  "name": "Copy page url",
  "version": "1.0",
  "description": "Copy page link to clipboard.",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icons/copu-48.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/copu-16.png",
      "32": "icons/copu-32.png",
      "48": "icons/copu-48.png",
      "64": "icons/copu-64.png"
    }
  },
  "permissions": [
    "contextMenus",
    "activeTab"
  ]
}