Add QuicFlagSaver to files in net/tools/quic/

net/tools/quic/quic_dispatcher_test.cc

Index: net/tools/quic/quic_dispatcher_test.cc
diff --git a/net/tools/quic/quic_dispatcher_test.cc b/net/tools/quic/quic_dispatcher_test.cc
index fcf45c2fadb90669f5d78f2a3bb96f5fe1c342b9..8875ee7ca949758348e83902cdad19885c2ff97d 100644
--- a/net/tools/quic/quic_dispatcher_test.cc
+++ b/net/tools/quic/quic_dispatcher_test.cc
@@ -304,6 +304,7 @@ class QuicDispatcherTest : public ::testing::Test {
     return client_hello.GetSerialized().AsStringPiece().as_string();
   }
 
+  QuicFlagSaver flags_;  // Save/restore all QUIC flag values.
   EpollServer eps_;
   QuicEpollConnectionHelper helper_;
   MockQuicConnectionHelper mock_helper_;