Remove PathCloseFrame, QuicPathId, DefaultPathId and InvalidPathId.

net/quic/core/quic_connection_test.cc

Index: net/quic/core/quic_connection_test.cc
diff --git a/net/quic/core/quic_connection_test.cc b/net/quic/core/quic_connection_test.cc
index a069d4e67c5e5fc4ce273eb6a11447b7abe39bc4..51e9f28f1bcd287f205396d3b3893305d0548aff 100644
--- a/net/quic/core/quic_connection_test.cc
+++ b/net/quic/core/quic_connection_test.cc
@@ -929,10 +929,6 @@ class QuicConnectionTest : public ::testing::TestWithParam<TestParams> {
     ProcessFramePacket(QuicFrame(frame));
   }
 
-  void ProcessPathClosePacket(QuicPathCloseFrame* frame) {
-    ProcessFramePacket(QuicFrame(frame));
-  }
-
   bool IsMissing(QuicPacketNumber number) {
     return IsAwaitingPacket(*outgoing_ack(), number, 0);
   }