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

webrtc/p2p/base/portallocator.cc

Index: webrtc/p2p/base/portallocator.cc
diff --git a/webrtc/p2p/base/portallocator.cc b/webrtc/p2p/base/portallocator.cc
index 76455b506e220ad8e3d188b827111ca19e7b12e3..35edade13c95325bb1011b0b041b0917e63f3773 100644
--- a/webrtc/p2p/base/portallocator.cc
+++ b/webrtc/p2p/base/portallocator.cc
@@ -21,8 +21,11 @@ PortAllocatorSession::PortAllocatorSession(const std::string& content_name,
       component_(component),
       flags_(flags),
       generation_(0),
-      username_(ice_ufrag),
-      password_(ice_pwd) {
+      // If PORTALLOCATOR_ENABLE_SHARED_UFRAG flag is not enabled, ignore the
+      // incoming ufrag and pwd, which will cause each Port to generate one
+      // by itself.
+      username_(flags_ & PORTALLOCATOR_ENABLE_SHARED_UFRAG ? ice_ufrag : ""),
+      password_(flags_ & PORTALLOCATOR_ENABLE_SHARED_UFRAG ? ice_pwd : "") {
 }
 
 PortAllocatorSession* PortAllocator::CreateSession(