Expose DtlsTransport::remote_ssl_certificates

Bug: chromium:907849
Change-Id: If990d541099edb9a327230e1d78a03b406269885
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/131951
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27558}
diff --git a/pc/dtls_transport.cc b/pc/dtls_transport.cc
index 38cef1e..9ce72a3 100644
--- a/pc/dtls_transport.cc
+++ b/pc/dtls_transport.cc
@@ -116,8 +116,15 @@
   RTC_DCHECK_RUN_ON(owner_thread_);
   rtc::CritScope scope(&lock_);
   if (internal_dtls_transport_) {
-    info_ = DtlsTransportInformation(
-        TranslateState(internal_dtls_transport_->dtls_state()));
+    if (internal_dtls_transport_->dtls_state() ==
+        cricket::DTLS_TRANSPORT_CONNECTED) {
+      info_ = DtlsTransportInformation(
+          TranslateState(internal_dtls_transport_->dtls_state()),
+          internal_dtls_transport_->GetRemoteSSLCertChain());
+    } else {
+      info_ = DtlsTransportInformation(
+          TranslateState(internal_dtls_transport_->dtls_state()));
+    }
   } else {
     info_ = DtlsTransportInformation(DtlsTransportState::kClosed);
   }