Deprecate rolled out flag: FLAGS_quic_allow_port_migration.

net/tools/quic/end_to_end_test.cc

Index: net/tools/quic/end_to_end_test.cc
diff --git a/net/tools/quic/end_to_end_test.cc b/net/tools/quic/end_to_end_test.cc
index 4c60cb39d7e5e43dbe6719aa3b8554c40a72f57c..fe1bbd1cb1f2c609e5012f7e8b345cc8a5da71c5 100644
--- a/net/tools/quic/end_to_end_test.cc
+++ b/net/tools/quic/end_to_end_test.cc
@@ -1162,8 +1162,6 @@ TEST_P(EndToEndTest, ConnectionMigrationClientPortChanged) {
   // Tests that the client's port can change during an established QUIC
   // connection, and that doing so does not result in the connection being
   // closed by the server.
-  FLAGS_quic_allow_port_migration = true;
-
   ASSERT_TRUE(Initialize());
 
   EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));