Since the pacer is always enabled, removing enable/disable which makes all packet queueing succeed. Also renaming one of the ::SendPackets ::InsertPacket to avoid confusion. BUG=webrtc:1695, webrtc:2629 R=stefan@webrtc.org Review URL: https://codereview.webrtc.org/1392513002 . Cr-Commit-Position: refs/heads/master@{#10211}