This structure is used outside Dlrr creating/parsing. but RTCPReceiveTimeInfo structure doesn't follow naming style. rtcp::ReceiveTimeInfo added to replace both Dlrr::SubBlock (when creating/parsing packets) and RTCPReceiveTimeInfo (for other uses). this CL is a split of https://codereview.webrtc.org/1557593002/ BUG=webrtc:5260 R=asapersson@webrtc.org, åsapersson Review URL: https://codereview.webrtc.org/1631683002 . Cr-Commit-Position: refs/heads/master@{#11380}