Send and receive color space information if available

Bug: webrtc:8651
Change-Id: I244647cb1ccbda66fce83ae925cf4273c5a6568b
Reviewed-on: https://webrtc-review.googlesource.com/c/112383
Commit-Queue: Johannes Kron <kron@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25884}
diff --git a/api/rtpparameters.h b/api/rtpparameters.h
index badda07..47df22e 100644
--- a/api/rtpparameters.h
+++ b/api/rtpparameters.h
@@ -309,6 +309,10 @@
   // https://tools.ietf.org/html/rfc6904
   static const char kEncryptHeaderExtensionsUri[];
 
+  // Header extension for color space information.
+  static const char kColorSpaceUri[];
+  static const int kColorSpaceDefaultId;
+
   // Inclusive min and max IDs for two-byte header extensions and one-byte
   // header extensions, per RFC8285 Section 4.2-4.3.
   static constexpr int kMinId = 1;