markdown-viewer/background/index.js

;(() => {
  var storage = md.storage(md)
  var inject = md.inject({storage})
  var detect = md.detect({storage, inject})
  var webrequest = md.webrequest({storage, detect})
  var mathjax = md.mathjax()
  var xhr = md.xhr()

  var compilers = Object.keys(md.compilers)
    .reduce((all, compiler) => (
      all[compiler] = md.compilers[compiler]({storage}),
      all
    ), {})

  var messages = md.messages({storage, compilers, mathjax, xhr, webrequest})

  chrome.tabs.onUpdated.addListener(detect.tab)
  chrome.runtime.onMessage.addListener(messages)

  if (chrome.webRequest) {
    webrequest.init()
  }
})()