Create //webrtc/api:libjingle_peerconnection_api + refactorings.

webrtc/pc/mediasession.cc

Index: webrtc/pc/mediasession.cc
diff --git a/webrtc/pc/mediasession.cc b/webrtc/pc/mediasession.cc
index 2f973deb7f6476a223d2b8713fa66906d18ba777..275b2cd962ecab688fbad8d321580934eaafbabe 100644
--- a/webrtc/pc/mediasession.cc
+++ b/webrtc/pc/mediasession.cc
@@ -1192,25 +1192,6 @@ static bool IsDtlsActive(
   return current_tdesc->secure();
 }
 
-std::string MediaTypeToString(MediaType type) {
-  std::string type_str;
-  switch (type) {
-    case MEDIA_TYPE_AUDIO:
-      type_str = "audio";
-      break;
-    case MEDIA_TYPE_VIDEO:
-      type_str = "video";
-      break;
-    case MEDIA_TYPE_DATA:
-      type_str = "data";
-      break;
-    default:
-      ASSERT(false);
-      break;
-  }
-  return type_str;
-}
-
 std::string MediaContentDirectionToString(MediaContentDirection direction) {
   std::string dir_str;
   switch (direction) {