Examine source code of HTTP Header Hack

{
  "manifest_version": 2,
  "name": "__MSG_extensionName__",
  "version": "0.1.1",
  "author": "Pankaj Aswal",
  "homepage_url": "https://electricalcodes.blogspot.com/",
  "default_locale": "en",
  "options_ui": {
    "page": "options.html"
  },
  "icons": {
    "64": "icons/64.png"
  },
  "description": "__MSG_extensionDescription__",
  "permissions": [
    "storage",
    "activeTab",
    "webRequest",
    "webRequestBlocking",
    "tabs",
    "downloads",
    "<all_urls>"
  ],
  "sidebar_action": {
    "default_icon": "icons/icon.svg",
    "default_title": "__MSG_extensionName__",
    "default_panel": "HTTPHeaderMain.html"
  },
  "browser_action": {
    "default_title": "__MSG_extensionName__",
    "default_icon": {
      "64": "icons/64.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3117c7b7-048b-4bc6-8b46-b79a60e215c4}"
    }
  }
}