Delete support for receiving RTCP RPSI and SLI messages.

webrtc/modules/rtp_rtcp/BUILD.gn

Index: webrtc/modules/rtp_rtcp/BUILD.gn
diff --git a/webrtc/modules/rtp_rtcp/BUILD.gn b/webrtc/modules/rtp_rtcp/BUILD.gn
index f2e53bbbfaeb1b3842275e8813add451d416b08a..541edd92583b1f536db3930f3449dee320d0ca90 100644
--- a/webrtc/modules/rtp_rtcp/BUILD.gn
+++ b/webrtc/modules/rtp_rtcp/BUILD.gn
@@ -74,8 +74,6 @@ rtc_static_library("rtp_rtcp") {
     "source/rtcp_packet/remb.h",
     "source/rtcp_packet/report_block.cc",
     "source/rtcp_packet/report_block.h",
-    "source/rtcp_packet/rpsi.cc",
-    "source/rtcp_packet/rpsi.h",
     "source/rtcp_packet/rrtr.cc",
     "source/rtcp_packet/rrtr.h",
     "source/rtcp_packet/rtpfb.cc",
@@ -84,8 +82,6 @@ rtc_static_library("rtp_rtcp") {
     "source/rtcp_packet/sdes.h",
     "source/rtcp_packet/sender_report.cc",
     "source/rtcp_packet/sender_report.h",
-    "source/rtcp_packet/sli.cc",
-    "source/rtcp_packet/sli.h",
     "source/rtcp_packet/target_bitrate.cc",
     "source/rtcp_packet/target_bitrate.h",
     "source/rtcp_packet/tmmb_item.cc",
@@ -255,11 +251,9 @@ if (rtc_include_tests) {
       "source/rtcp_packet/receiver_report_unittest.cc",
       "source/rtcp_packet/remb_unittest.cc",
       "source/rtcp_packet/report_block_unittest.cc",
-      "source/rtcp_packet/rpsi_unittest.cc",
       "source/rtcp_packet/rrtr_unittest.cc",
       "source/rtcp_packet/sdes_unittest.cc",
       "source/rtcp_packet/sender_report_unittest.cc",
-      "source/rtcp_packet/sli_unittest.cc",
       "source/rtcp_packet/target_bitrate_unittest.cc",
       "source/rtcp_packet/tmmbn_unittest.cc",
       "source/rtcp_packet/tmmbr_unittest.cc",