code: function updateMinimizedStyleMap(
      doc,
      element,
      originalStyleMap,
      minimizedStyleMap,
      pseudo) {
    var currentComputedStyle = doc.defaultView.getComputedStyle(element, pseudo);
    var foundNewRequiredStyle = false;
    for (var property in originalStyleMap) {
      var originalValue = originalStyleMap[property];
      if (originalValue != currentComputedStyle.getPropertyValue(property)) {
        minimizedStyleMap[property] = originalValue;
        foundNewRequiredStyle = true;
      }
    }
    return foundNewRequiredStyle;
  }
docs: We compare the original computed style with the minimized computed style
  and update |minimizedStyleMap| based on any differences.
  
  @param {Document} doc The Document that contains the rendered HTML.
  @param {Element} element The Element whose style attributes should be
  minimized.
  @param {Object<string, string>} originalStyleMap A map representing the
  original computed style values. The keys are style attribute property
  names. The values are the corresponding property values.
  @param {Object<string, string>} minimizedStyleMap A map representing the
  minimized style values. The keys are style attribute property names. The
  values are the corresponding property values.
  @param {string} pseudo If the style describes an ordinary
  Element, then |pseudo| will be set to null.  If the style describes a
  pseudo element, then |pseudo| will be the string that represents that
  pseudo element.
  @return {boolean} Returns true if minimizedStyleMap was changed. Returns false
  otherwise.