Updated WebRTC version to 3.42
Updated WebRTC version to 3.42

R=mallinath@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2271004

Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 038e8e64ef60e4f036c6f51fb07c653e1a8da0d4

sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc,sippet/webrtc