text: /* global chrome */
  
  var metaDataCallback = null
  
  chrome.runtime.onMessage.addListener(function (details, sender, sendResponse) {
    metaDataCallback(details)
  })
  
  window.getSocialCardMetaData = function (callback) {
    metaDataCallback = callback
    chrome.tabs.executeScript(null, {
      file: 'content.js'
    })
  }
  