Style fixes in rtcp_packet/

webrtc/modules/rtp_rtcp/source/rtcp_packet/tmmbr.cc

Index: webrtc/modules/rtp_rtcp/source/rtcp_packet/tmmbr.cc
diff --git a/webrtc/modules/rtp_rtcp/source/rtcp_packet/tmmbr.cc b/webrtc/modules/rtp_rtcp/source/rtcp_packet/tmmbr.cc
index 0ba131187b34ad235aa389408d9bca7430825be3..fd0719ea5ea3c752d94e7326c275e2b1ff301812 100644
--- a/webrtc/modules/rtp_rtcp/source/rtcp_packet/tmmbr.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtcp_packet/tmmbr.cc
@@ -43,6 +43,11 @@ constexpr uint8_t Tmmbr::kFeedbackMessageType;
 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 //  | MxTBR Exp |  MxTBR Mantissa                 |Measured Overhead|
 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+Tmmbr::Tmmbr() = default;
+
+Tmmbr::~Tmmbr() = default;
+
 bool Tmmbr::Parse(const CommonHeader& packet) {
   RTC_DCHECK_EQ(packet.type(), kPacketType);
   RTC_DCHECK_EQ(packet.fmt(), kFeedbackMessageType);
@@ -75,6 +80,11 @@ void Tmmbr::AddTmmbr(const TmmbItem& item) {
   items_.push_back(item);
 }
 
+size_t Tmmbr::BlockLength() const {
+  return kHeaderLength + kCommonFeedbackLength +
+         TmmbItem::kLength * items_.size();
+}
+
 bool Tmmbr::Create(uint8_t* packet,
                    size_t* index,
                    size_t max_length,