rtc::Buffer: Accept void* in addition to the byte-sized types
rtc::Buffer: Accept void* in addition to the byte-sized types

We used to accept void* (until 9478437f), and we'll have to continue
to do so for a little while longer, until Chromium doesn't need it
anymore.

TBR=tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/48179004

Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#9035}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 011c00f708f1bdcbecf6c941343e090f378f09a6

Alkalyne/webrtctrunk,jchavanton/webrtc,krieger-od/webrtc,krieger-od/webrtc,jchavanton/webrtc,aleonliao/webrtc-trunk,aleonliao/webrtc-trunk,sippet/webrtc,jchavanton/webrtc,Alkalyne/webrtctrunk,jchavanton/webrtc,sippet/webrtc,krieger-od/webrtc,aleonliao/webrtc-trunk,krieger-od/webrtc,Alkalyne/webrtctrunk,aleonliao/webrtc-trunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,sippet/webrtc,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,sippet/webrtc,sippet/webrtc,Alkalyne/webrtctrunk,sippet/webrtc,aleonliao/webrtc-trunk,jchavanton/webrtc,krieger-od/webrtc,aleonliao/webrtc-trunk,krieger-od/webrtc,jchavanton/webrtc,jchavanton/webrtc