The function iterated over two containers, destroyed their elements
and popped those elements one at a time. It's more efficient to
destroy all of the elements, then clear() the container.
Bug: None
Change-Id: I17aa88694ee41df64c5793b08b96899b7ff04071
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/133901
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Elad Alon <eladalon@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27730}
e1068c1bc9