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: refs/heads/master@{#8790}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 17c64d1c9632c7d7901bf9002af028e5880f8bf4
1 file changed