Examine source code of YouTube use Flash Player

{
  "name": "YouTube™ use Flash Player",
  "short_name": "iyfplayer",
  "description": "Force YouTube to use Flash player over the HTML5 player",
  "author": "James Fray",
  "version": "0.1.3resigned1",
  "manifest_version": 2,
  "permissions": [
    "storage",
    "tabs"
  ],
  "background": {
    "scripts": [
      "common.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*"
      ],
      "js": [
        "data/inject.js"
      ],
      "run_at": "document_start",
      "all_frames": false
    }
  ],
  "homepage_url": "http://add0n.com/youtube-tools.html?from=flash",
  "icons": {
    "16": "data/icons/16.png",
    "48": "data/icons/48.png",
    "128": "data/icons/128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3cb66f33-d9c7-441e-9f24-82ce974ba6b2}"
    }
  }
}