Replace StunMessage's vector<StunAttribute*>* with a
vector<unique_ptr<StunAttribute>> as suggested in a TODO.

BUG=NONE

Review-Url: https://codereview.webrtc.org/2735523002
Cr-Original-Commit-Position: refs/heads/master@{#17076}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: ad94c4c5d9e3e3766a80e32551c877878049e1d3
2 files changed