To ease use of WebRTC in other codebases, update some macros to match glibc's ansidecl.h, which uses double-underscores for attributes. NOTRY=True Review URL: https://codereview.webrtc.org/1571653002 Cr-Commit-Position: refs/heads/master@{#11185}
Review URL: https://codereview.webrtc.org/1494133003 Cr-Commit-Position: refs/heads/master@{#11042}