Let QUIC be able to add random padding of [1,256] bytes after fin is consumed for a stream. Random …

net/quic/core/quic_packet_generator.h

Index: net/quic/core/quic_packet_generator.h
diff --git a/net/quic/core/quic_packet_generator.h b/net/quic/core/quic_packet_generator.h
index 676691c5513bdb38257038d9de448240828e6cc5..bd4604c58c3f37d62fb764d2035152cdc88b8be8 100644
--- a/net/quic/core/quic_packet_generator.h
+++ b/net/quic/core/quic_packet_generator.h
@@ -73,6 +73,7 @@ class QUIC_EXPORT_PRIVATE QuicPacketGenerator {
 
   QuicPacketGenerator(QuicConnectionId connection_id,
                       QuicFramer* framer,
+                      QuicRandom* random_generator,
                       QuicBufferAllocator* buffer_allocator,
                       DelegateInterface* delegate);
 
@@ -92,11 +93,14 @@ class QUIC_EXPORT_PRIVATE QuicPacketGenerator {
   // mode, these packets will also be sent during this call.
   // |delegate| (if not nullptr) will be informed once all packets sent as a
   // result of this call are ACKed by the peer.
+  // When |state| is FIN_AND_PADDING, random padding of size [1, 256] will be
+  // added after stream frames. If current constructed packet cannot
+  // accommodate, the padding will overflow to the next packet(s).
   QuicConsumedData ConsumeData(
       QuicStreamId id,
       QuicIOVector iov,
       QuicStreamOffset offset,
-      bool fin,
+      StreamSendingState state,
       QuicReferenceCountedPointer<QuicAckListenerInterface> ack_listener);
 
   // Sends as many data only packets as allowed by the send algorithm and the
@@ -196,6 +200,13 @@ class QUIC_EXPORT_PRIVATE QuicPacketGenerator {
   // fit into current open packet.
   bool AddNextPendingFrame();
 
+  // Adds a random amount of padding (between 1 to 256 bytes).
+  void AddRandomPadding();
+
+  // Sends remaining pending padding.
+  // Pending paddings should only be sent when there is nothing else to send.
+  void SendRemainingPendingPadding();
+
   DelegateInterface* delegate_;
 
   QuicPacketCreator packet_creator_;
@@ -213,6 +224,8 @@ class QUIC_EXPORT_PRIVATE QuicPacketGenerator {
   // retransmitted.
   QuicStopWaitingFrame pending_stop_waiting_frame_;
 
+  QuicRandom* random_generator_;
+
   DISALLOW_COPY_AND_ASSIGN(QuicPacketGenerator);
 };