Remove or narrow down some unnecessary includes.

PiperOrigin-RevId: 441231060
diff --git a/quiche/common/platform/default/quiche_platform_impl/quic_flags_impl.h b/quiche/common/platform/default/quiche_platform_impl/quic_flags_impl.h
index 2d7af12..a7d9bb7 100644
--- a/quiche/common/platform/default/quiche_platform_impl/quic_flags_impl.h
+++ b/quiche/common/platform/default/quiche_platform_impl/quic_flags_impl.h
@@ -8,7 +8,6 @@
 #include <string>
 
 #include "quiche/common/platform/api/quiche_export.h"
-#include "quiche/common/platform/api/quiche_flags.h"
 
 #define QUIC_PROTOCOL_FLAG(type, flag, ...) \
   QUICHE_EXPORT_PRIVATE extern type FLAGS_##flag;
diff --git a/quiche/quic/test_tools/simulator/quic_endpoint.h b/quiche/quic/test_tools/simulator/quic_endpoint.h
index db23ece..e1a8c3e 100644
--- a/quiche/quic/test_tools/simulator/quic_endpoint.h
+++ b/quiche/quic/test_tools/simulator/quic_endpoint.h
@@ -9,7 +9,7 @@
 #include "quiche/quic/core/crypto/null_decrypter.h"
 #include "quiche/quic/core/crypto/null_encrypter.h"
 #include "quiche/quic/core/quic_connection.h"
-#include "quiche/quic/core/quic_default_packet_writer.h"
+#include "quiche/quic/core/quic_packet_writer.h"
 #include "quiche/quic/core/quic_packets.h"
 #include "quiche/quic/core/quic_stream_frame_data_producer.h"
 #include "quiche/quic/core/quic_trace_visitor.h"
diff --git a/quiche/quic/test_tools/simulator/quic_endpoint_base.h b/quiche/quic/test_tools/simulator/quic_endpoint_base.h
index f4931c7..26bb014 100644
--- a/quiche/quic/test_tools/simulator/quic_endpoint_base.h
+++ b/quiche/quic/test_tools/simulator/quic_endpoint_base.h
@@ -11,7 +11,7 @@
 #include "quiche/quic/core/crypto/null_decrypter.h"
 #include "quiche/quic/core/crypto/null_encrypter.h"
 #include "quiche/quic/core/quic_connection.h"
-#include "quiche/quic/core/quic_default_packet_writer.h"
+#include "quiche/quic/core/quic_packet_writer.h"
 #include "quiche/quic/core/quic_packets.h"
 #include "quiche/quic/core/quic_stream_frame_data_producer.h"
 #include "quiche/quic/core/quic_trace_visitor.h"