Examine source code of Qt Screen Capture

{
  "manifest_version": 2,
  "name": "Qt Screen Capture",
  "description": "The screenshot extension that gets the job done.",
  "version": "1.0.3",
  "permissions": [
    "storage",
    "downloads",
    "alarms",
    "activeTab",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "img/icon16.png",
    "19": "img/icon19.png",
    "32": "img/icon32.png",
    "38": "img/icon38.png",
    "48": "img/icon48.png",
    "128": "img/icon128.png"
  },
  "commands": {
    "screenshot_currentScreen": {
      "description": "Screenshot - Current screen"
    },
    "screenshot_rectScreen": {
      "description": "Screenshot - Area on screen"
    },
    "screenshot_rectPage": {
      "description": "Screenshot - Area on page"
    },
    "screenshot_scrollElement": {
      "description": "Screenshot - Scrollable-Element"
    },
    "screenshot_element": {
      "description": "Screenshot - Element"
    },
    "media_showPageImage": {
      "description": "Page media - Show image"
    },
    "media_createVideoScreenshot": {
      "description": "Page media - Create video screenshot"
    },
    "zoom": {
      "description": "Page Zoom"
    }
  }
}