Parse the connection data in SDP (c= line).

webrtc/p2p/base/sessiondescription.h

Index: webrtc/p2p/base/sessiondescription.h
diff --git a/webrtc/p2p/base/sessiondescription.h b/webrtc/p2p/base/sessiondescription.h
index a20f7b71321a9b0cfd395bcd55c701775879a200..2cde4fb77bafcc3ecc381abc95fc761a52a30388 100644
--- a/webrtc/p2p/base/sessiondescription.h
+++ b/webrtc/p2p/base/sessiondescription.h
@@ -14,8 +14,10 @@
 #include <string>
 #include <vector>
 
-#include "webrtc/p2p/base/transportinfo.h"
 #include "webrtc/base/constructormagic.h"
+#include "webrtc/base/optional.h"
+#include "webrtc/base/socketaddress.h"
+#include "webrtc/p2p/base/transportinfo.h"
 
 namespace cricket {
 
@@ -180,11 +182,23 @@ class SessionDescription {
   void set_msid_supported(bool supported) { msid_supported_ = supported; }
   bool msid_supported() const { return msid_supported_; }
 
+  void set_session_connection_addr(

[Taylor Brandstetter, 2017/03/10 22:41:17]

I think it would be simpler to only store this address in
MediaContentDescription. If a "c=" is found at the session level, its value can
just be copied to the media level, since the meaning is the same.

This is what currently happens with ice-ufrag at the session level (for
example):
https://cs.chromium.org/chromium/src/third_party/webrtc/pc/webrtcsdp.cc?type=...

[Zhi Huang, 2017/03/15 04:04:59]

Done.

+      const rtc::Optional<rtc::SocketAddress>& addr) {
+    session_connection_addr_ = addr;
+  }
+  rtc::Optional<rtc::SocketAddress> session_connection_addr() {
+    return session_connection_addr_;
+  }
+
  private:
   ContentInfos contents_;
   TransportInfos transport_infos_;
   ContentGroups content_groups_;
   bool msid_supported_ = true;
+  // https://tools.ietf.org/html/rfc4566#page-21
+  // The session level connection data indicating the address of the remote
+  // endpoint.
+  rtc::Optional<rtc::SocketAddress> session_connection_addr_;
 };
 
 // Indicates whether a ContentDescription was an offer or an answer, as