傾きに合わせて画像を回転する

Imagerotation.user.js

// ==UserScript==
// @name           Rotate Images
// @namespace      http://june29.jp/
// @include        *
// ==/UserScript==

(function() {
  var style = document.createElement('style');
  document.body.appendChild(style);
  style.textContent = "img, canvas, video, object {\n" + "-moz-transform: rotate(0deg);\n" + "  }";

  var offset = {};
  window.addEventListener("MozOrientation", function(data) {

    if (!offset.x) offset.x = data.x;
    if (!offset.y) offset.y = data.y;
    if (!offset.z) offset.z = data.z;
    var radian = -1 * (data.x - offset.x) * 90;

    style.sheet.cssRules[0].style.MozTransform = 'rotate(' + radian + 'deg)';
  }, true);
})();