Remove hardcoded kValueSizeBytes values from variable-length header extensions.

webrtc/modules/rtp_rtcp/source/flexfec_sender.cc

Index: webrtc/modules/rtp_rtcp/source/flexfec_sender.cc
diff --git a/webrtc/modules/rtp_rtcp/source/flexfec_sender.cc b/webrtc/modules/rtp_rtcp/source/flexfec_sender.cc
index 4aec05662fdaae852192570d7c9ca64dcb4a2776..03ca2b80b66b5ecc1af57e4061a1cc813674dbdb 100644
--- a/webrtc/modules/rtp_rtcp/source/flexfec_sender.cc
+++ b/webrtc/modules/rtp_rtcp/source/flexfec_sender.cc
@@ -147,8 +147,9 @@ std::vector<std::unique_ptr<RtpPacketToSend>> FlexfecSender::GetFecPackets() {
 }
 
 // The overhead is BWE RTP header extensions and FlexFEC header.
-size_t FlexfecSender::MaxPacketOverhead() const {
-  return rtp_header_extension_map_.GetTotalLengthInBytes() +
+size_t FlexfecSender::MaxPacketOverhead(
+    rtc::ArrayView<const RtpExtensionSize> extension_sizes) const {
+  return rtp_header_extension_map_.GetTotalLengthInBytes(extension_sizes) +
          kFlexfecMaxHeaderSize;
 }