Previously, it was only possible to free PeerConnectionObserverJni
objects using this method. Now it is generic and can free any
PeerConnectionObserver.
Bug: webrtc:8662
Change-Id: I619ca5ed88a0c2553fa6d19ce41e510947d5bd44
Reviewed-on: https://webrtc-review.googlesource.com/35222
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Commit-Queue: Sami Kalliomäki <sakal@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21411}