Examine source code of Reddit First Level Comment

{
  "manifest_version": 2,
  "name": "Reddit Comment Collapser",
  "version": "1.6",
  "description": "Collapses all but the first-level comments on Reddit. Rank comments by points. Drag and drop links to open in new tab. Drag selected text to web search. Mouse gesture to close tab, forward or back. Click icon for clock. Redirect from reddit.com to old.reddit.com",
  "permissions": [
    "tabs",
    "browserSettings",
    "webRequest",
    "webRequestBlocking",
    "*://www.reddit.com/*",
    "*://reddit.com/*"
  ],
  "icons": {
    "48": "icons/border-48.png"
  },
  "browser_action": {
    "default_icon": "icons/border-48.png",
    "default_popup": "popup.html",
    "default_title": "Reddit Comment Collapser"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.reddit.com/*"
      ],
      "js": [
        "reddit-comment-collapser.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "drag-link-newtab.js"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "mouse-gesture.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{879dbedf-9641-46c8-9e70-6d2cdc7e04d0}"
    }
  }
}