We had a few JavaScript unit tests which were broken, with two specific

causes:

For the ScrollManagerView, chrome has been doing sub-pixel

  scrolling, which broke our tests. I've sprinkled some Math.round()

  calls around to fix this.
For the ReviewReplyEditorModel, an update to Backbone had broken

  some tests which artificially assign an ID in order for isNew() to

  return false. The newer isNew() checks the id attribute

  instead of the value in the object.

Ran js-tests.