1. GetTransportFeedbackVector will now return a vector which also explicitly states lost packets. 2. The returned vector is unsorted (uses default order - by sequence number). It's up to the users to sort otherwise, if they need a different order. BUG=None Review-Url: https://codereview.webrtc.org/2707383006 Cr-Commit-Position: refs/heads/master@{#17114}