It appears that the adapt_frame_drops, effects_frame_drops, and capturer_frame_time statistics are never used. They are collected by cricket::VideoCapturer, and copied into VideoSenderInfo by the VideoMediaChannel::GetStats method.
So delete the code to generate the statistics, and the VariableInfo template which had no other uses.
BUG=webrtc:5426
R=pbos@webrtc.org, pthatcher@webrtc.org
Review URL: https://codereview.webrtc.org/1804133003 .
Cr-Commit-Position: refs/heads/master@{#12032}
505945aed7