Delete unused index variable. No behavior change.

net/quic/core/quic_unacked_packet_map.cc

Index: net/quic/core/quic_unacked_packet_map.cc
diff --git a/net/quic/core/quic_unacked_packet_map.cc b/net/quic/core/quic_unacked_packet_map.cc
index 79235d254cdccee2a8d96256b521e339311bbcbc..7dc5a853280e94884e3eea50030900aa7ecd26a7 100644
--- a/net/quic/core/quic_unacked_packet_map.cc
+++ b/net/quic/core/quic_unacked_packet_map.cc
@@ -25,10 +25,8 @@ QuicUnackedPacketMap::QuicUnackedPacketMap()
       pending_crypto_packet_count_(0) {}
 
 QuicUnackedPacketMap::~QuicUnackedPacketMap() {
-  QuicPacketNumber index = least_unacked_;
-  for (UnackedPacketMap::iterator it = unacked_packets_.begin();
-       it != unacked_packets_.end(); ++it, ++index) {
-    DeleteFrames(&it->retransmittable_frames);
+  for (QuicTransmissionInfo& transmission_info : unacked_packets_) {
+    DeleteFrames(&(transmission_info.retransmittable_frames));
   }
 }