Revert of Change the size of the ICE ufrag to 4 bytes

webrtc/p2p/base/p2pconstants.cc

Index: webrtc/p2p/base/p2pconstants.cc
diff --git a/webrtc/p2p/base/p2pconstants.cc b/webrtc/p2p/base/p2pconstants.cc
index 64e5a13cf8b3132aa738c2519c3c931d51c5146c..fd75984a08e93b114cabde2b66780c3e41dc7c25 100644
--- a/webrtc/p2p/base/p2pconstants.cc
+++ b/webrtc/p2p/base/p2pconstants.cc
@@ -21,8 +21,9 @@
 
 const char GROUP_TYPE_BUNDLE[] = "BUNDLE";
 
-// Minimum ufrag length is 4 characters as per RFC5245.
-const int ICE_UFRAG_LENGTH = 4;
+// Minimum ufrag length is 4 characters as per RFC5245. We chose 16 because
+// some internal systems expect username to be 16 bytes.
+const int ICE_UFRAG_LENGTH = 16;
 // Minimum password length of 22 characters as per RFC5245. We chose 24 because
 // some internal systems expect password to be multiple of 4.
 const int ICE_PWD_LENGTH = 24;