Adding codecs to the RtpParameters returned by an RtpSender.

Contains every field except for sdpFmtpLine.
Setting a reordered list of codecs is not yet supported.

R=glaznev@webrtc.org, pthatcher@webrtc.org, skvlad@webrtc.org, tkchin@webrtc.org

Review URL: https://codereview.webrtc.org/1885473004 .

Cr-Commit-Position: refs/heads/master@{#12453}
diff --git a/webrtc/api/objc/RTCRtpParameters.h b/webrtc/api/objc/RTCRtpParameters.h
index 91d8108..7b66f37 100644
--- a/webrtc/api/objc/RTCRtpParameters.h
+++ b/webrtc/api/objc/RTCRtpParameters.h
@@ -10,6 +10,7 @@
 
 #import <Foundation/Foundation.h>
 
+#import "webrtc/api/objc/RTCRtpCodecParameters.h"
 #import "webrtc/api/objc/RTCRtpEncodingParameters.h"
 #import "webrtc/base/objc/RTCMacros.h"
 
@@ -21,6 +22,9 @@
 /** The currently active encodings in the order of preference. */
 @property(nonatomic, copy) NSArray<RTCRtpEncodingParameters *> *encodings;
 
+/** The negotiated set of send codecs in order of preference. */
+@property(nonatomic, copy) NSArray<RTCRtpCodecParameters *> *codecs;
+
 - (instancetype)init NS_DESIGNATED_INITIALIZER;
 
 @end