Remove path id from IV in QUIC encrytion algorithms.

net/quic/core/crypto/aead_base_encrypter.cc

Index: net/quic/core/crypto/aead_base_encrypter.cc
diff --git a/net/quic/core/crypto/aead_base_encrypter.cc b/net/quic/core/crypto/aead_base_encrypter.cc
index 1420b009b160de25dd618a707e3c799702cee976..33183898928b54e68460b95df325abfbe5d0ee16 100644
--- a/net/quic/core/crypto/aead_base_encrypter.cc
+++ b/net/quic/core/crypto/aead_base_encrypter.cc
@@ -103,7 +103,6 @@ bool AeadBaseEncrypter::Encrypt(StringPiece nonce,
 }
 
 bool AeadBaseEncrypter::EncryptPacket(QuicVersion /*version*/,
-                                      QuicPathId path_id,
                                       QuicPacketNumber packet_number,
                                       StringPiece associated_data,
                                       StringPiece plaintext,
@@ -119,10 +118,8 @@ bool AeadBaseEncrypter::EncryptPacket(QuicVersion /*version*/,
   const size_t nonce_size = nonce_prefix_size_ + sizeof(packet_number);
   QUIC_ALIGNED(4) char nonce_buffer[kMaxNonceSize];
   memcpy(nonce_buffer, nonce_prefix_, nonce_prefix_size_);
-  uint64_t path_id_packet_number =
-      QuicUtils::PackPathIdAndPacketNumber(path_id, packet_number);
-  memcpy(nonce_buffer + nonce_prefix_size_, &path_id_packet_number,
-         sizeof(path_id_packet_number));
+  memcpy(nonce_buffer + nonce_prefix_size_, &packet_number,
+         sizeof(packet_number));
 
   if (!Encrypt(StringPiece(nonce_buffer, nonce_size), associated_data,
                plaintext, reinterpret_cast<unsigned char*>(output))) {