Revert "Reland "Remove GICE (gone forever!) and PORTALLOCATOR_ENABLE_SHARED_UFRAG (enabled forever)…

webrtc/p2p/client/basicportallocator.cc

Index: webrtc/p2p/client/basicportallocator.cc
diff --git a/webrtc/p2p/client/basicportallocator.cc b/webrtc/p2p/client/basicportallocator.cc
index f90c52164ccda049a4a873698f6c857b3524726b..e52c5847d4bfd066c4293aea0aab8ef19b46baf3 100644
--- a/webrtc/p2p/client/basicportallocator.cc
+++ b/webrtc/p2p/client/basicportallocator.cc
@@ -692,6 +692,14 @@ AllocationSequence::AllocationSequence(BasicPortAllocatorSession* session,
 }
 
 bool AllocationSequence::Init() {
+  if (IsFlagSet(PORTALLOCATOR_ENABLE_SHARED_SOCKET) &&
+      !IsFlagSet(PORTALLOCATOR_ENABLE_SHARED_UFRAG)) {
+    LOG(LS_ERROR) << "Shared socket option can't be set without "
+                  << "shared ufrag.";
+    ASSERT(false);
+    return false;
+  }
+
   if (IsFlagSet(PORTALLOCATOR_ENABLE_SHARED_SOCKET)) {
     udp_socket_.reset(session_->socket_factory()->CreateUdpSocket(
         rtc::SocketAddress(ip_, 0), session_->allocator()->min_port(),