Examine source code of Constant Contexting

{
  "name": "Constant Contexting",
  "description": "Highlights elements with keywords on developer.chrome",
  "version": "1.4",
  "page_action": {
    "default_icon": {
      "16": "images/cc16.png",
      "32": "images/cc32.png"
    },
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "images/cc16.png",
    "32": "images/cc32.png",
    "48": "images/cc48.png",
    "128": "images/cc128.png"
  },
  "permissions": [
    "https://developer.chrome.com/*",
    "storage",
    "declarativeContent"
  ],
  "manifest_version": 2,
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "web_accessible_resources": [
    "style.css"
  ],
  "content_scripts": [
    {
      "all_frames": true,
      "js": [
        "content_script.js"
      ],
      "matches": [
        "https://developer.chrome.com/*"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{5d5fef61-029b-4443-97f6-21b9f9e9883d}"
    }
  }
}