Remove hardcoded kValueSizeBytes values from variable-length header extensions.

webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h

Index: webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
diff --git a/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h b/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
index 11bc9433a45709dd73255d0d0f3c64766488a613..103704cbb3493e77bda429121fc0f3168c75f3b7 100644
--- a/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
+++ b/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
@@ -128,6 +128,16 @@ enum RtxMode {
 
 const size_t kRtxHeaderSize = 2;
 
+struct RTPExtensionSizeInfo {

[danilchap, 2017/05/08 16:25:06]

may be RtpExtensionSize or RtpHeaderExtensionSize:
RTP -> Rtp to follow style guide (even if lots of types around do not)
drop Info because it doesn't seems to add descriptiveness and does look like
help avoiding name conflict.

[erikvarga1, 2017/05/09 11:40:03]

Done. I saw RTP in a few places so I thought that was the norm.

[danilchap, 2017/05/09 12:33:48]

May be hide this struct in less public header and move it closer to where it is
used.
e.g. to rtp_header_extension.h

[erikvarga1, 2017/05/09 13:30:30]

Done.

+  RTPExtensionType type;
+  uint8_t value_size;
+};
+
+template <typename Extension>
+constexpr RTPExtensionSizeInfo CreateExtensionSizeInfo() {

[danilchap, 2017/05/08 16:25:06]

planning to use this function outside of the rtp_rtcp module?

[erikvarga1, 2017/05/09 11:40:03]

I don't think so. This is used solely for the RTP extension overhead
calculation, so it shouldn't really be needed in other modules.

[danilchap, 2017/05/09 12:33:48]

Then do not declare it here:
it seems you use it in rtp_sender.cc and in a test.
Declare it just in rtp_sender.cc where you use it and in the test feel free to
inline the body.

[erikvarga1, 2017/05/09 13:30:30]

Done.

+  return {Extension::kId, Extension::kValueSizeBytes};
+}
+
 struct RTCPSenderInfo {
     uint32_t NTPseconds;
     uint32_t NTPfraction;