Delete class webrtc::VideoRenderer and its header file.

To replace the SmoothsRenderedFrames method, added a corresponding
flag to VideoReceiveStream::Config instead.

BUG=webrtc:5426

Review URL: https://codereview.webrtc.org/1818023002

Cr-Original-Commit-Position: refs/heads/master@{#12102}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 7ade7b3282aa18177768b1615719e67cc4ba87ce
19 files changed