Spotify Key and BPM Finder

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "manifest_version": 2,
  "name": "Spotify Key and BPM Finder",
  "description": "Display key and BPM for songs found on spotify",
  "version": "1.0.8",
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Click here!"
  },
  "permissions": [
    "identity",
    "tabs",
    "webNavigation",
    "https://*.spotify.com/*",
    "*://*.google.com/*",
    "storage",
    "alarms"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*.spotify.com/*"
      ],
      "js": [
        "content_script.js"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    "/oauth2/*"
  ],
  "background": {
    "scripts": [
      "eventPage.js"
    ],
    "persistent": false
  },
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self' https://*.spotify.com/*"
}