Like the chrome.bookmarks.onRemoved.addListener call at http://code.google.com/chrome/extensions/bookmarks.html#event-onRemoved but guaranteed to fire even if the onremove event fired on a containing folder

chrome-addBookmarkRemoveListener.js

// makes sure fn gets called when bm_id is removed, whether it was a direct kill
// or it got caught in collateral damage from a recursive bookmark removal spree
function addBookmarkRemoveListener(bm_id, fn) {
  // as we won't get an onRemoved callback for bm_id when any of its parents got
  // removed recursively, keep a list of all its parents to know when to fire fn
  function indexParentsFor(bm_id, bookmarks) {
    function bookmarkParents(id, bms, path) {
      ////console.log('bookmarkParents(', id, bms, path, ')');
      for (var i = 0, bm, found; bm = bms[i]; i++) {
        if (bm.id === id) return path;
        if (bm.url) continue;
        if ((found = bookmarkParents(id, bm.children, path.concat(bm.id)))) {
          //console.info('found: ', found, ')');
          return found;
        }
      }
      return null;
    }
    ///console.log('indexParentsFor(', bm_id, bookmarks, ')');
    return parent_ids[bm_id] = bookmarkParents(bm_id, bookmarks, []);
  }

  function register(bm_id, fn) {
    //console.log('addBookmarkRemoveListener.register(', bm_id, fn, ')');
    var parents = parent_ids[bm_id];
    if (parents) { // already indexed?
      if (!parents.some(strictlyEquals(fn)))
        callbacks[bm_id].push(fn);
    }
    else {
      callbacks[bm_id] = (callbacks[bm_id] || []).concat(fn);
      chrome.bookmarks.getTree(function(bms) { indexParentsFor(bm_id, bms); });
    }
  }

  function strictlyEquals(x) { return function(y) { return x === y; }; }

  // array of all bm_id:s we are tracking
  function idsTracked() {
    var ids = [];
    for (var id in parent_ids)
      if (Number(id) !== NaN)
        ids.push(id);
    return ids;
  }

  // refresh parent_id cache post-move
  function onMove(bm_id, info) {
    //console.log('onMove(', bm_id, info, ')');
    function reindex(bookmarks) {
      for (var i = 0, id, ids = idsTracked(); id = ids[i]; i++) {
        indexParentsFor(bm_id, bookmarks);
      }
    }
    chrome.bookmarks.getTree(reindex);
  }

  // when one or more of the bookmarks we track is removed, call their listeners
  // and remove their associated data from our list of tracked ids and callbacks
  function onRemove(bm_id, info) {
    //console.log('onRemove(', bm_id, info, ')');
    var is_bm_id = strictlyEquals(bm_id);
    for (var i = 0, id, ids = idsTracked(); id = ids[i]; i++) {
      if (id !== bm_id && !parent_ids[id].some(is_bm_id)) continue;

      for (var j = 0, fn, fns = callbacks[id]; fn = fns[j]; j++)
        fn(bm_id, Object.create(info));
      delete parent_ids[id];
      delete callbacks[id];
    }
  }

  var self       = addBookmarkRemoveListener,
      callbacks  = self.callbacks = self.callbacks || {},   // id => array<fn>
      parent_ids = self.parent_ids = self.parent_ids || {}; // id => array<id>

  self.onMove = self.onMove || // only add our listener for onMoved once
    (onMove, chrome.bookmarks.onMoved.addListener(onMove)); // reindex bookmarks
  self.onRemoved = self.onRemove || // only add our listener for onRemoved once
    (onRemove, chrome.bookmarks.onRemoved.addListener(onRemove)); // real worker

  register(bm_id, fn); // index the parents for this bm_id and register its fn
}