Update flag count and comment for --gfe2_reloadable_flag_quic_connection_migration_use_new_cid_v2

PiperOrigin-RevId: 379308220

quic/core/quic_connection.cc

diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index de6361e..ce99e65 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -2028,12 +2028,14 @@
 }
 
 void QuicConnection::OnClientConnectionIdAvailable() {
-  QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 3, 5);
   QUICHE_DCHECK(perspective_ == Perspective::IS_SERVER);
   if (!peer_issued_cid_manager_->HasUnusedConnectionId()) {
     return;
   }
   if (default_path_.client_connection_id.IsEmpty()) {
+    // Count client connection ID patched onto the default path.
+    QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 3,
+                                 6);
     const QuicConnectionIdData* unused_cid_data =
         peer_issued_cid_manager_->ConsumeOneUnusedConnectionId();
     QUIC_DVLOG(1) << ENDPOINT << "Patch connection ID "
@@ -2049,6 +2051,9 @@
   }
   if (alternative_path_.peer_address.IsInitialized() &&
       alternative_path_.client_connection_id.IsEmpty()) {
+    // Count client connection ID patched onto the alternative path.
+    QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 4,
+                                 6);
     const QuicConnectionIdData* unused_cid_data =
         peer_issued_cid_manager_->ConsumeOneUnusedConnectionId();
     QUIC_DVLOG(1) << ENDPOINT << "Patch connection ID "
@@ -2142,6 +2147,8 @@
     return false;
   }
   QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_support_multiple_cids_v4, 2, 2);
+  // Count successfully received RETIRE_CONNECTION_ID frames.
+  QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 5, 6);
   return true;
 }
 
@@ -6829,8 +6836,6 @@
         {default_path_.server_connection_id,
          alternative_path_.server_connection_id});
   } else {
-    QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 4,
-                                 5);
     peer_issued_cid_manager_->MaybeRetireUnusedConnectionIds(
         {default_path_.client_connection_id,
          alternative_path_.client_connection_id});

quic/core/quic_dispatcher.cc

diff --git a/quic/core/quic_dispatcher.cc b/quic/core/quic_dispatcher.cc
index 7e0cded..de5cb83 100644
--- a/quic/core/quic_dispatcher.cc
+++ b/quic/core/quic_dispatcher.cc
@@ -1070,7 +1070,8 @@
         << server_connection_id << " new_connection_id: " << new_connection_id;
     return;
   }
-  QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 5, 5);
+  // Count new connection ID added to the dispatcher map.
+  QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 6, 6);
   auto insertion_result = reference_counted_session_map_.insert(
       std::make_pair(new_connection_id, it->second));
   QUICHE_DCHECK(insertion_result.second);

quic/core/quic_session.cc

diff --git a/quic/core/quic_session.cc b/quic/core/quic_session.cc
index 3c0b964..c473ced 100644
--- a/quic/core/quic_session.cc
+++ b/quic/core/quic_session.cc
@@ -2105,14 +2105,16 @@
 }
 
 void QuicSession::SendNewConnectionId(const QuicNewConnectionIdFrame& frame) {
-  QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 1, 5);
+  // Count NEW_CONNECTION_ID frames sent to client.
+  QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 1, 6);
   control_frame_manager_.WriteOrBufferNewConnectionId(
       frame.connection_id, frame.sequence_number, frame.retire_prior_to,
       frame.stateless_reset_token);
 }
 
 void QuicSession::SendRetireConnectionId(uint64_t sequence_number) {
-  QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 2, 5);
+  // Count RETIRE_CONNECTION_ID frames sent to client.
+  QUIC_RELOADABLE_FLAG_COUNT_N(quic_connection_migration_use_new_cid_v2, 2, 6);
   control_frame_manager_.WriteOrBufferRetireConnectionId(sequence_number);
 }