Use unique_ptr in webrtcsdp.cc
Use unique_ptr in webrtcsdp.cc

Bug: None
Change-Id: I68c1d1bbde928667b215340e2b1a6133b344d179
Reviewed-on: https://webrtc-review.googlesource.com/c/114907
Reviewed-by: Amit Hilbuch <d2550ade90c131f91745c9e77cef0b6abfbee93c@webrtc.org>
Commit-Queue: Steve Anton <93f73658da16553b94c040887a439a155812e54e@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#26052}
TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc