Remove some deprecated functions. BUG=webrtc:6402 Review-Url: https://codereview.webrtc.org/2859223003 Cr-Commit-Position: refs/heads/master@{#18116}
Without this, every time WebRtcVideoEngine2 calls supported_codecs(), the codec list grows. BUG=webrtc:7020 Review-Url: https://codereview.webrtc.org/2639423006 Cr-Commit-Position: refs/heads/master@{#16178}