Examine source code of Link Mode Switcher

{
  "manifest_version": 2,
  "name": "Link Mode Switcher",
  "version": "1.5",
  "description": "タブごとにリンクの開き方を切り替える（中クリックでモード切り替え）",
  "permissions": [
    "tabs",
    "storage",
    "contextMenus",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_title": "リンク開きモード切替",
    "default_icon": {
      "16": "icons/icon_default.png"
    },
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_script.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7b0683c2-1f4a-4009-9b3a-e03b7824e5b2}"
    }
  }
}