Removes unused PacketFeedbackComparator

Bug: webrtc:9883
Change-Id: I0a24e54b02984a30a6d961ec83662742d3088ec5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/143162
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28352}
diff --git a/modules/rtp_rtcp/include/rtp_rtcp_defines.h b/modules/rtp_rtcp/include/rtp_rtcp_defines.h
index d666ab4..d53a698 100644
--- a/modules/rtp_rtcp/include/rtp_rtcp_defines.h
+++ b/modules/rtp_rtcp/include/rtp_rtcp_defines.h
@@ -276,17 +276,6 @@
   uint16_t rtp_sequence_number;
 };
 
-class PacketFeedbackComparator {
- public:
-  inline bool operator()(const PacketFeedback& lhs, const PacketFeedback& rhs) {
-    if (lhs.arrival_time_ms != rhs.arrival_time_ms)
-      return lhs.arrival_time_ms < rhs.arrival_time_ms;
-    if (lhs.send_time_ms != rhs.send_time_ms)
-      return lhs.send_time_ms < rhs.send_time_ms;
-    return lhs.sequence_number < rhs.sequence_number;
-  }
-};
-
 struct RtpPacketSendInfo {
  public:
   RtpPacketSendInfo() = default;