Remove some references to gQUIC Padded Ping. Padded Ping is still sent by gQUIC clients as a connectivity check, but we're not shipping any new gQUIC clients, so SerializeGQuicConnectivityProbingPacket could be removed completely removed if you prefer. PiperOrigin-RevId: 830589310

diff --git a/quiche/quic/core/quic_connection.cc b/quiche/quic/core/quic_connection.cc
index b91d006..b765488 100644
--- a/quiche/quic/core/quic_connection.cc
+++ b/quiche/quic/core/quic_connection.cc

@@ -5190,9 +5190,9 @@
 
   std::unique_ptr<SerializedPacket> probing_packet;
   if (!version().HasIetfQuicFrames()) {
-    // Non-IETF QUIC, generate a padded ping regardless of whether this is a
+    // For gQUIC, generate a padded ping regardless of whether this is a
     // request or a response.
-    probing_packet = packet_creator_.SerializeConnectivityProbingPacket();
+    probing_packet = packet_creator_.SerializeGQuicConnectivityProbingPacket();
   } else {
     // IETF QUIC path challenge.
     // Send a path probe request using IETF QUIC PATH_CHALLENGE frame.

diff --git a/quiche/quic/core/quic_connection.h b/quiche/quic/core/quic_connection.h
index 689852e..2539953 100644
--- a/quiche/quic/core/quic_connection.h
+++ b/quiche/quic/core/quic_connection.h

@@ -1082,9 +1082,7 @@
   // Sends a connectivity probing packet to |peer_address| with
   // |probing_writer|. If |probing_writer| is nullptr, will use default
   // packet writer to write the packet. Returns true if subsequent packets can
-  // be written to the probing writer. If connection is V99, a padded IETF QUIC
-  // PATH_CHALLENGE packet is transmitted; if not V99, a Google QUIC padded PING
-  // packet is transmitted.
+  // be written to the probing writer.
   virtual bool SendConnectivityProbingPacket(
       QuicPacketWriter* probing_writer, const QuicSocketAddress& peer_address);
 
@@ -1224,16 +1222,6 @@
   // packets have been successfully processed.
   bool MaybeProcessCoalescedPackets();
 
-  enum PacketContent : uint8_t {
-    NO_FRAMES_RECEIVED,
-    // TODO(fkastenholz): Change name when we get rid of padded ping/
-    // pre-version-99.
-    // Also PATH CHALLENGE and PATH RESPONSE.
-    FIRST_FRAME_IS_PING,
-    SECOND_FRAME_IS_PADDING,
-    NOT_PADDED_PING,  // Set if the packet is not {PING, PADDING}.
-  };
-
   // Whether the handshake completes from this connection's perspective.
   bool IsHandshakeComplete() const;
 

diff --git a/quiche/quic/core/quic_packet_creator.cc b/quiche/quic/core/quic_packet_creator.cc
index e81d548..018c1ae 100644
--- a/quiche/quic/core/quic_packet_creator.cc
+++ b/quiche/quic/core/quic_packet_creator.cc

@@ -902,7 +902,7 @@
 }
 
 std::unique_ptr<SerializedPacket>
-QuicPacketCreator::SerializeConnectivityProbingPacket() {
+QuicPacketCreator::SerializeGQuicConnectivityProbingPacket() {
   QUIC_BUG_IF(quic_bug_12398_11,
               VersionHasIetfQuicFrames(framer_->transport_version()))
       << ENDPOINT

diff --git a/quiche/quic/core/quic_packet_creator.h b/quiche/quic/core/quic_packet_creator.h
index c07dd8d..8fff612 100644
--- a/quiche/quic/core/quic_packet_creator.h
+++ b/quiche/quic/core/quic_packet_creator.h

@@ -243,8 +243,8 @@
   bool AddPaddedSavedFrame(const QuicFrame& frame,
                            TransmissionType transmission_type);
 
-  // Creates a connectivity probing packet for versions prior to version 99.
-  std::unique_ptr<SerializedPacket> SerializeConnectivityProbingPacket();
+  // Creates a connectivity probing packet for gQUIC.
+  std::unique_ptr<SerializedPacket> SerializeGQuicConnectivityProbingPacket();
 
   // Create connectivity probing request and response packets using PATH
   // CHALLENGE and PATH RESPONSE frames, respectively, for version 99/IETF QUIC.

diff --git a/quiche/quic/core/quic_packet_creator_test.cc b/quiche/quic/core/quic_packet_creator_test.cc
index 380b3d5..dc31a77 100644
--- a/quiche/quic/core/quic_packet_creator_test.cc
+++ b/quiche/quic/core/quic_packet_creator_test.cc

@@ -961,7 +961,7 @@
     encrypted =
         creator_.SerializePathChallengeConnectivityProbingPacket(payload);
   } else {
-    encrypted = creator_.SerializeConnectivityProbingPacket();
+    encrypted = creator_.SerializeGQuicConnectivityProbingPacket();
   }
   {
     InSequence s;
@@ -3958,7 +3958,7 @@
     probing_packet =
         creator_.SerializePathChallengeConnectivityProbingPacket(payload);
   } else {
-    probing_packet = creator_.SerializeConnectivityProbingPacket();
+    probing_packet = creator_.SerializeGQuicConnectivityProbingPacket();
   }
 
   ASSERT_TRUE(simple_framer_.ProcessPacket(QuicEncryptedPacket(

diff --git a/quiche/quic/test_tools/quic_connection_peer.h b/quiche/quic/test_tools/quic_connection_peer.h
index 2b284fa..c5fbddf 100644
--- a/quiche/quic/test_tools/quic_connection_peer.h
+++ b/quiche/quic/test_tools/quic_connection_peer.h

@@ -139,8 +139,6 @@
   static void SetMaxConsecutiveNumPacketsWithNoRetransmittableFrames(
       QuicConnection* connection, size_t new_value);
   static bool SupportsReleaseTime(QuicConnection* connection);
-  static QuicConnection::PacketContent GetCurrentPacketContent(
-      QuicConnection* connection);
   static void AddBytesReceived(QuicConnection* connection, size_t length);
   static void SetAddressValidated(QuicConnection* connection);
 

diff --git a/quiche/quic/test_tools/quic_packet_creator_peer.cc b/quiche/quic/test_tools/quic_packet_creator_peer.cc
index 0847b32..ea4fd9b 100644
--- a/quiche/quic/test_tools/quic_packet_creator_peer.cc
+++ b/quiche/quic/test_tools/quic_packet_creator_peer.cc

@@ -116,13 +116,6 @@
 
 // static
 std::unique_ptr<SerializedPacket>
-QuicPacketCreatorPeer::SerializeConnectivityProbingPacket(
-    QuicPacketCreator* creator) {
-  return creator->SerializeConnectivityProbingPacket();
-}
-
-// static
-std::unique_ptr<SerializedPacket>
 QuicPacketCreatorPeer::SerializePathChallengeConnectivityProbingPacket(
     QuicPacketCreator* creator, const QuicPathFrameBuffer& payload) {
   return creator->SerializePathChallengeConnectivityProbingPacket(payload);