Update from chromium https://crrev.com/301725/

net/quic/quic_network_transaction_unittest.cc

Index: net/quic/quic_network_transaction_unittest.cc
diff --git a/net/quic/quic_network_transaction_unittest.cc b/net/quic/quic_network_transaction_unittest.cc
index 9d12a018585a074e896e2fbee318739d34c2f948..ab698f39629aa756e42f9a3beda43559801e8539 100644
--- a/net/quic/quic_network_transaction_unittest.cc
+++ b/net/quic/quic_network_transaction_unittest.cc
@@ -121,12 +121,12 @@ class QuicNetworkTransactionTest
     clock_->AdvanceTime(QuicTime::Delta::FromMilliseconds(20));
   }
 
-  virtual void SetUp() {
+  void SetUp() override {
     NetworkChangeNotifier::NotifyObserversOfIPAddressChangeForTests();
     base::MessageLoop::current()->RunUntilIdle();
   }
 
-  virtual void TearDown() {
+  void TearDown() override {
     NetworkChangeNotifier::NotifyObserversOfIPAddressChangeForTests();
     // Empty the current queue.
     base::MessageLoop::current()->RunUntilIdle();