Revert "Put ViEFrameProviderBase::DeliverFrame back in the critical section in ViECapturer::DeliverI420Frame"
Revert "Put ViEFrameProviderBase::DeliverFrame back in the critical section in ViECapturer::DeliverI420Frame"

This reverts commit r8724.

Reason for revert: This was not the cause of the tsan issues.

BUG=1128
R=mflodman@webrtc.org, pbos@webrtc.org, tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/50389004

Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#8790}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 17c64d1c9632c7d7901bf9002af028e5880f8bf4

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