[rtp_rtcp] rtcp::Fir cleaned and got Parse function.

webrtc/modules/rtp_rtcp/source/rtcp_packet.h

Index: webrtc/modules/rtp_rtcp/source/rtcp_packet.h
diff --git a/webrtc/modules/rtp_rtcp/source/rtcp_packet.h b/webrtc/modules/rtp_rtcp/source/rtcp_packet.h
index 965a667304a8ebc02ab57fc0b455e2d6601f8298..33064aac1581019dcf965f067e86d66f8ddf7405 100644
--- a/webrtc/modules/rtp_rtcp/source/rtcp_packet.h
+++ b/webrtc/modules/rtp_rtcp/source/rtcp_packet.h
@@ -38,11 +38,10 @@ class RawPacket;
 //
 //  Fir fir;
 //  fir.From(123);
-//  fir.To(234)
-//  fir.WithCommandSeqNum(123);
+//  fir.WithRequestTo(234, 56);
 //
 //  size_t length = 0;                     // Builds an intra frame request
-//  uint8_t packet[kPacketSize];           // with sequence number 123.
+//  uint8_t packet[kPacketSize];           // with sequence number 56.
 //  fir.Build(packet, &length, kPacketSize);
 //
 //  RawPacket packet = fir.Build();        // Returns a RawPacket holding