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}