Implement current/pending session description methods.

webrtc/api/peerconnection.cc

Index: webrtc/api/peerconnection.cc
diff --git a/webrtc/api/peerconnection.cc b/webrtc/api/peerconnection.cc
index aeb03c64921890c339c0f1a0f3362679dd60ceb6..bba42cfdbdf4351e541734c6e9d70f02d63b9b67 100644
--- a/webrtc/api/peerconnection.cc
+++ b/webrtc/api/peerconnection.cc
@@ -1388,6 +1388,26 @@ const SessionDescriptionInterface* PeerConnection::remote_description() const {
   return session_->remote_description();
 }
 
+const SessionDescriptionInterface* PeerConnection::current_local_description()
+    const {
+  return session_->current_local_description();
+}
+
+const SessionDescriptionInterface* PeerConnection::current_remote_description()
+    const {
+  return session_->current_remote_description();
+}
+
+const SessionDescriptionInterface* PeerConnection::pending_local_description()
+    const {
+  return session_->pending_local_description();
+}
+
+const SessionDescriptionInterface* PeerConnection::pending_remote_description()
+    const {
+  return session_->pending_remote_description();
+}
+
 void PeerConnection::Close() {
   TRACE_EVENT0("webrtc", "PeerConnection::Close");
   // Update stats here so that we have the most recent stats for tracks and