/WebM Looper/icon.png
http://i.imgur.com/ayMrOD8.png

/WebM Looper/loopWebM.js
?//// Courtesy of The Chromium Authors. All rights reserved.
?//   Made by an anon for other anons
?var videoWrapper = document.getElementsByTagName("video")[0];
?videoWrapper.loop = true;
?videoWrapper.controls = false;

/WebM Looper/manifest.json
?{
?"manifest_version": 2,

?"name": "AutoWebM Looper",
?"description": "This extension loops WebM files automatically",
?"version": "1.0",
??"permissions": [
??"tabs",
??"*://*/*.webm",
??"file:///*/*.webm"
?],

?"content_scripts": [
?{
??"matches": ["*://*/*.webm","file:///*/*.webm"],
??"js": ["loopWebM.js"],
??"run_at": "document_end"
?}
?],

?"icons": { "128": "icon.png" }
?}