Remove deprected functions from EncodedImageCallback and RtpRtcp

Removed EncodedImageCallback::Encoded() and RtpRtcp::SendOutgoingData().
These methods should no longer be used anywhere and it's safe to remove
them.

BUG=chromium:621691

Review-Url: https://codereview.webrtc.org/2405173006
Cr-Original-Commit-Position: refs/heads/master@{#14902}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: fa565842718ad178a7562721b25d916fbabc2b92
15 files changed