tree a3977f82fe805ce48f245e14808e507900b79b08
parent 041f27516a06c25bc8360c50cc8b6eb481f4299f
author Sameer Agarwal <sameeragarwal@google.com> 1401395622 -0700
committer Sameer Agarwal <sameeragarwal@google.com> 1401400526 -0700

Flesh out OrderedGroups.

1. Add the ability to bulk remove elements.
2. Add accessor for elements_to_group.
3. Early exit in Remove if there are no elements.

Change-Id: I3df1f00de05338a42e9907423b674469a022d3bc