Polymer/observe-js — pull request #74 by jmesserly (2014-09-25 18:29:28+00:00)
Title: improve performance for template repeat over model objects with shared prototype

This fixes the case presented in: https://github.com/Polymer/polymer-dev/issues/101

The diff includes https://github.com/Polymer/observe-js/pull/73 but I can rebase against master if that one doesn't land first.

What is happening there is we have a bunch of paths inside a `