Added architecture for compiling under chrome NaCl.
Added architecture for compiling under chrome NaCl.

R=tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/8899004

Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 242102517dcbec4c8e696226425bd5619d8d3cb3

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