Automatically Change Html Attributes On Page Load

I am trying to create a Google Chrome custom theme (an image displayed on the new tab page). However there are these little last visited boxes blocking out part of the image, and t

Solution 1:

in your manifest.json

"permissions":["<all_urls>"],"content_scripts":[{"matches":["http://*/*","https://*/*"],"js":["content.js"],"run_at":"document_end"// pay attention to this line}],

and in your content.js

(function(window, chrome){
  "use strict";
  var doc = window.document;
  doc.getElementById("mv-tiles").style.opacity = "0";
}(window, chrome));