Examine source code of Math in Address Bar

{
  "name": "Math",
  "author": "Terry Yuen",
  "version": "0.1.3resigned1",
  "description": "Solve math equations in the address bar by typing 'math' then something like: (sqrt(5)-1)/cos(rad(72))",
  "manifest_version": 2,
  "icons": {
    "16": "icon_16.png",
    "24": "icon_24.png",
    "38": "icon_38.png",
    "48": "icon_48.png",
    "96": "icon_96.png"
  },
  "applications": {
    "gecko": {
      "strict_min_version": "52.0",
      "id": "{1e440f63-c444-43d4-bece-a3080f56c898}"
    }
  },
  "omnibox": {
    "keyword": "math"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "page_action": {
    "browser_style": true,
    "default_icon": {
      "19": "icon_16.png",
      "24": "icon_24.png",
      "38": "icon_38.png"
    },
    "default_popup": "popup.html"
  }
}