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Unused function when building Chromium, triggered build errors when
importing webrtc.

BUG=
R=tommi@webrtc.org

Review URL: https://codereview.webrtc.org/1471073005 .

Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#10768}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 97c821dc56a3cfa3674936b012c10b91fd6ea00e

aleonliao/webrtc-trunk,aleonliao/webrtc-trunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,aleonliao/webrtc-trunk,aleonliao/webrtc-trunk,aleonliao/webrtc-trunk,jchavanton/webrtc,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,jchavanton/webrtc,Alkalyne/webrtctrunk,jchavanton/webrtc,Alkalyne/webrtctrunk,jchavanton/webrtc,jchavanton/webrtc,aleonliao/webrtc-trunk,Alkalyne/webrtctrunk,jchavanton/webrtc,jchavanton/webrtc