Privatize useful.h and avl.h
diff --git a/test/core/end2end/tests/authority_not_supported.cc b/test/core/end2end/tests/authority_not_supported.cc
index 9c85450..f2852f7 100644
--- a/test/core/end2end/tests/authority_not_supported.cc
+++ b/test/core/end2end/tests/authority_not_supported.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/bad_hostname.cc b/test/core/end2end/tests/bad_hostname.cc
index 85e9ba1..63bfd76 100644
--- a/test/core/end2end/tests/bad_hostname.cc
+++ b/test/core/end2end/tests/bad_hostname.cc
@@ -26,7 +26,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/gpr/string.h"
 #include "test/core/end2end/cq_verifier.h"
 
diff --git a/test/core/end2end/tests/bad_ping.cc b/test/core/end2end/tests/bad_ping.cc
index 30a1b8d..672c2f4 100644
--- a/test/core/end2end/tests/bad_ping.cc
+++ b/test/core/end2end/tests/bad_ping.cc
@@ -25,8 +25,8 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/thd.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
+#include "src/core/lib/gpr/useful.h"
 #include "test/core/end2end/cq_verifier.h"
 
 #define MAX_PING_STRIKES 1
diff --git a/test/core/end2end/tests/binary_metadata.cc b/test/core/end2end/tests/binary_metadata.cc
index 381671e..8a0d667 100644
--- a/test/core/end2end/tests/binary_metadata.cc
+++ b/test/core/end2end/tests/binary_metadata.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/call_creds.cc b/test/core/end2end/tests/call_creds.cc
index c5ea101..968dab1 100644
--- a/test/core/end2end/tests/call_creds.cc
+++ b/test/core/end2end/tests/call_creds.cc
@@ -26,7 +26,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
+
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/security/credentials/credentials.h"
 #include "test/core/end2end/cq_verifier.h"
diff --git a/test/core/end2end/tests/cancel_after_accept.cc b/test/core/end2end/tests/cancel_after_accept.cc
index f59caf7..11bf4e7 100644
--- a/test/core/end2end/tests/cancel_after_accept.cc
+++ b/test/core/end2end/tests/cancel_after_accept.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/slice/slice_internal.h"
diff --git a/test/core/end2end/tests/cancel_after_client_done.cc b/test/core/end2end/tests/cancel_after_client_done.cc
index 9b832d4..b0702b7 100644
--- a/test/core/end2end/tests/cancel_after_client_done.cc
+++ b/test/core/end2end/tests/cancel_after_client_done.cc
@@ -25,7 +25,8 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
+
+#include "src/core/lib/gpr/useful.h"
 #include "test/core/end2end/cq_verifier.h"
 #include "test/core/end2end/tests/cancel_test_helpers.h"
 
diff --git a/test/core/end2end/tests/cancel_after_invoke.cc b/test/core/end2end/tests/cancel_after_invoke.cc
index d3891b1..a3e36e0 100644
--- a/test/core/end2end/tests/cancel_after_invoke.cc
+++ b/test/core/end2end/tests/cancel_after_invoke.cc
@@ -25,7 +25,8 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
+
+#include "src/core/lib/gpr/useful.h"
 #include "test/core/end2end/cq_verifier.h"
 #include "test/core/end2end/tests/cancel_test_helpers.h"
 
diff --git a/test/core/end2end/tests/cancel_after_round_trip.cc b/test/core/end2end/tests/cancel_after_round_trip.cc
index b10b939..63e6505 100644
--- a/test/core/end2end/tests/cancel_after_round_trip.cc
+++ b/test/core/end2end/tests/cancel_after_round_trip.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/slice/slice_internal.h"
diff --git a/test/core/end2end/tests/cancel_before_invoke.cc b/test/core/end2end/tests/cancel_before_invoke.cc
index 1112375..e9fa046 100644
--- a/test/core/end2end/tests/cancel_before_invoke.cc
+++ b/test/core/end2end/tests/cancel_before_invoke.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/cancel_in_a_vacuum.cc b/test/core/end2end/tests/cancel_in_a_vacuum.cc
index a6c534e..6be2d69 100644
--- a/test/core/end2end/tests/cancel_in_a_vacuum.cc
+++ b/test/core/end2end/tests/cancel_in_a_vacuum.cc
@@ -25,7 +25,8 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
+
+#include "src/core/lib/gpr/useful.h"
 #include "test/core/end2end/cq_verifier.h"
 #include "test/core/end2end/tests/cancel_test_helpers.h"
 
diff --git a/test/core/end2end/tests/cancel_with_status.cc b/test/core/end2end/tests/cancel_with_status.cc
index 7937fd1..6820ba5 100644
--- a/test/core/end2end/tests/cancel_with_status.cc
+++ b/test/core/end2end/tests/cancel_with_status.cc
@@ -27,7 +27,6 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/gpr/string.h"
 #include "test/core/end2end/cq_verifier.h"
 
diff --git a/test/core/end2end/tests/compressed_payload.cc b/test/core/end2end/tests/compressed_payload.cc
index c08653b..39491d8 100644
--- a/test/core/end2end/tests/compressed_payload.cc
+++ b/test/core/end2end/tests/compressed_payload.cc
@@ -28,7 +28,6 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/surface/call.h"
diff --git a/test/core/end2end/tests/default_host.cc b/test/core/end2end/tests/default_host.cc
index 7c94420..33be5f1 100644
--- a/test/core/end2end/tests/default_host.cc
+++ b/test/core/end2end/tests/default_host.cc
@@ -26,7 +26,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/gpr/string.h"
 #include "test/core/end2end/cq_verifier.h"
 
diff --git a/test/core/end2end/tests/disappearing_server.cc b/test/core/end2end/tests/disappearing_server.cc
index 29fb194..1b2f729 100644
--- a/test/core/end2end/tests/disappearing_server.cc
+++ b/test/core/end2end/tests/disappearing_server.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/empty_batch.cc b/test/core/end2end/tests/empty_batch.cc
index c41e65d..1de4b8f 100644
--- a/test/core/end2end/tests/empty_batch.cc
+++ b/test/core/end2end/tests/empty_batch.cc
@@ -26,7 +26,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/gpr/string.h"
 #include "test/core/end2end/cq_verifier.h"
 
diff --git a/test/core/end2end/tests/filter_call_init_fails.cc b/test/core/end2end/tests/filter_call_init_fails.cc
index 8f46f0b..f60a47f 100644
--- a/test/core/end2end/tests/filter_call_init_fails.cc
+++ b/test/core/end2end/tests/filter_call_init_fails.cc
@@ -27,7 +27,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/channel/channel_stack_builder.h"
 #include "src/core/lib/surface/channel_init.h"
 #include "test/core/end2end/cq_verifier.h"
diff --git a/test/core/end2end/tests/filter_causes_close.cc b/test/core/end2end/tests/filter_causes_close.cc
index ec8f9db..43f20d7 100644
--- a/test/core/end2end/tests/filter_causes_close.cc
+++ b/test/core/end2end/tests/filter_causes_close.cc
@@ -26,7 +26,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/channel/channel_stack_builder.h"
 #include "src/core/lib/surface/channel_init.h"
 #include "test/core/end2end/cq_verifier.h"
diff --git a/test/core/end2end/tests/filter_latency.cc b/test/core/end2end/tests/filter_latency.cc
index 845cbc0..d6cf3b0 100644
--- a/test/core/end2end/tests/filter_latency.cc
+++ b/test/core/end2end/tests/filter_latency.cc
@@ -27,7 +27,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_stack_builder.h"
 #include "src/core/lib/surface/channel_init.h"
diff --git a/test/core/end2end/tests/filter_status_code.cc b/test/core/end2end/tests/filter_status_code.cc
index 61c658b..ad80f23 100644
--- a/test/core/end2end/tests/filter_status_code.cc
+++ b/test/core/end2end/tests/filter_status_code.cc
@@ -27,7 +27,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_stack_builder.h"
 #include "src/core/lib/surface/call.h"
diff --git a/test/core/end2end/tests/graceful_server_shutdown.cc b/test/core/end2end/tests/graceful_server_shutdown.cc
index bf11b49..3b6872b 100644
--- a/test/core/end2end/tests/graceful_server_shutdown.cc
+++ b/test/core/end2end/tests/graceful_server_shutdown.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/high_initial_seqno.cc b/test/core/end2end/tests/high_initial_seqno.cc
index d4d4f5a..989cd56 100644
--- a/test/core/end2end/tests/high_initial_seqno.cc
+++ b/test/core/end2end/tests/high_initial_seqno.cc
@@ -27,7 +27,6 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
 #include "src/core/lib/gpr/string.h"
 #include "test/core/end2end/cq_verifier.h"
diff --git a/test/core/end2end/tests/hpack_size.cc b/test/core/end2end/tests/hpack_size.cc
index 0d6ec01..66b3a40 100644
--- a/test/core/end2end/tests/hpack_size.cc
+++ b/test/core/end2end/tests/hpack_size.cc
@@ -27,9 +27,9 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
 #include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gpr/useful.h"
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/idempotent_request.cc b/test/core/end2end/tests/idempotent_request.cc
index 7487e4d..578510d 100644
--- a/test/core/end2end/tests/idempotent_request.cc
+++ b/test/core/end2end/tests/idempotent_request.cc
@@ -26,7 +26,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
+
 #include "src/core/lib/gpr/string.h"
 #include "test/core/end2end/cq_verifier.h"
 
diff --git a/test/core/end2end/tests/invoke_large_request.cc b/test/core/end2end/tests/invoke_large_request.cc
index 8a67e3c..b7afa97 100644
--- a/test/core/end2end/tests/invoke_large_request.cc
+++ b/test/core/end2end/tests/invoke_large_request.cc
@@ -26,7 +26,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
+
+#include "src/core/lib/gpr/useful.h"
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/keepalive_timeout.cc b/test/core/end2end/tests/keepalive_timeout.cc
index 6482b86..0cdd12e 100644
--- a/test/core/end2end/tests/keepalive_timeout.cc
+++ b/test/core/end2end/tests/keepalive_timeout.cc
@@ -25,10 +25,11 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
+
 #include "src/core/ext/transport/chttp2/transport/frame_ping.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/gpr/env.h"
+#include "src/core/lib/gpr/useful.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "test/core/end2end/cq_verifier.h"
 
diff --git a/test/core/end2end/tests/large_metadata.cc b/test/core/end2end/tests/large_metadata.cc
index 8ddf433..c1343f9 100644
--- a/test/core/end2end/tests/large_metadata.cc
+++ b/test/core/end2end/tests/large_metadata.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/load_reporting_hook.cc b/test/core/end2end/tests/load_reporting_hook.cc
index e056bd5..cfe5814 100644
--- a/test/core/end2end/tests/load_reporting_hook.cc
+++ b/test/core/end2end/tests/load_reporting_hook.cc
@@ -24,7 +24,6 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
 #include "src/core/ext/filters/load_reporting/server_load_reporting_filter.h"
 #include "src/core/ext/filters/load_reporting/server_load_reporting_plugin.h"
diff --git a/test/core/end2end/tests/max_concurrent_streams.cc b/test/core/end2end/tests/max_concurrent_streams.cc
index c053973..642c0f7 100644
--- a/test/core/end2end/tests/max_concurrent_streams.cc
+++ b/test/core/end2end/tests/max_concurrent_streams.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/max_connection_age.cc b/test/core/end2end/tests/max_connection_age.cc
index ddccfc3..df5fd5c 100644
--- a/test/core/end2end/tests/max_connection_age.cc
+++ b/test/core/end2end/tests/max_connection_age.cc
@@ -24,8 +24,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
+#include "src/core/lib/gpr/useful.h"
 #include "test/core/end2end/cq_verifier.h"
 
 #define MAX_CONNECTION_AGE_MS 500
diff --git a/test/core/end2end/tests/max_connection_idle.cc b/test/core/end2end/tests/max_connection_idle.cc
index 293ff7d..09b4a54 100644
--- a/test/core/end2end/tests/max_connection_idle.cc
+++ b/test/core/end2end/tests/max_connection_idle.cc
@@ -25,8 +25,8 @@
 #include <grpc/support/log.h>
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
+#include "src/core/lib/gpr/useful.h"
 #include "test/core/end2end/cq_verifier.h"
 
 #define MAX_CONNECTION_IDLE_MS 500
diff --git a/test/core/end2end/tests/max_message_length.cc b/test/core/end2end/tests/max_message_length.cc
index e581f1f..b1757a9 100644
--- a/test/core/end2end/tests/max_message_length.cc
+++ b/test/core/end2end/tests/max_message_length.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/slice/slice_internal.h"
diff --git a/test/core/end2end/tests/negative_deadline.cc b/test/core/end2end/tests/negative_deadline.cc
index b752bf9..b28bee0 100644
--- a/test/core/end2end/tests/negative_deadline.cc
+++ b/test/core/end2end/tests/negative_deadline.cc
@@ -26,7 +26,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/gpr/string.h"
 #include "test/core/end2end/cq_verifier.h"
 
diff --git a/test/core/end2end/tests/network_status_change.cc b/test/core/end2end/tests/network_status_change.cc
index 7d0318f..809f8ff 100644
--- a/test/core/end2end/tests/network_status_change.cc
+++ b/test/core/end2end/tests/network_status_change.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 /* this is a private API but exposed here for testing*/
diff --git a/test/core/end2end/tests/no_logging.cc b/test/core/end2end/tests/no_logging.cc
index d89918b..b4908d4 100644
--- a/test/core/end2end/tests/no_logging.cc
+++ b/test/core/end2end/tests/no_logging.cc
@@ -27,7 +27,6 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/gpr/string.h"
 #include "src/core/lib/iomgr/error.h"
 #include "test/core/end2end/cq_verifier.h"
diff --git a/test/core/end2end/tests/no_op.cc b/test/core/end2end/tests/no_op.cc
index 18c2367..020f842 100644
--- a/test/core/end2end/tests/no_op.cc
+++ b/test/core/end2end/tests/no_op.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/payload.cc b/test/core/end2end/tests/payload.cc
index 2e9513b..3535d80 100644
--- a/test/core/end2end/tests/payload.cc
+++ b/test/core/end2end/tests/payload.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/ping.cc b/test/core/end2end/tests/ping.cc
index 725a425..c01dfa8 100644
--- a/test/core/end2end/tests/ping.cc
+++ b/test/core/end2end/tests/ping.cc
@@ -22,8 +22,8 @@
 #include <grpc/support/sync.h>
 #include <grpc/support/thd.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
+#include "src/core/lib/gpr/useful.h"
 #include "test/core/end2end/cq_verifier.h"
 
 #define PING_NUM 5
diff --git a/test/core/end2end/tests/ping_pong_streaming.cc b/test/core/end2end/tests/ping_pong_streaming.cc
index ec7981f..714a768 100644
--- a/test/core/end2end/tests/ping_pong_streaming.cc
+++ b/test/core/end2end/tests/ping_pong_streaming.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/proxy_auth.cc b/test/core/end2end/tests/proxy_auth.cc
index 495151b..c34505c 100644
--- a/test/core/end2end/tests/proxy_auth.cc
+++ b/test/core/end2end/tests/proxy_auth.cc
@@ -31,7 +31,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/gpr/string.h"
 #include "test/core/end2end/cq_verifier.h"
 
diff --git a/test/core/end2end/tests/registered_call.cc b/test/core/end2end/tests/registered_call.cc
index cefa89d..d1c37dc 100644
--- a/test/core/end2end/tests/registered_call.cc
+++ b/test/core/end2end/tests/registered_call.cc
@@ -26,7 +26,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
+
 #include "src/core/lib/gpr/string.h"
 #include "test/core/end2end/cq_verifier.h"
 
diff --git a/test/core/end2end/tests/request_with_flags.cc b/test/core/end2end/tests/request_with_flags.cc
index 984d8b1..4602313 100644
--- a/test/core/end2end/tests/request_with_flags.cc
+++ b/test/core/end2end/tests/request_with_flags.cc
@@ -25,7 +25,8 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
+
+#include "src/core/lib/gpr/useful.h"
 #include "src/core/lib/transport/byte_stream.h"
 #include "test/core/end2end/cq_verifier.h"
 
diff --git a/test/core/end2end/tests/request_with_payload.cc b/test/core/end2end/tests/request_with_payload.cc
index b3b9ee5..28818c8 100644
--- a/test/core/end2end/tests/request_with_payload.cc
+++ b/test/core/end2end/tests/request_with_payload.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/resource_quota_server.cc b/test/core/end2end/tests/resource_quota_server.cc
index 0ee014f..6d35d08 100644
--- a/test/core/end2end/tests/resource_quota_server.cc
+++ b/test/core/end2end/tests/resource_quota_server.cc
@@ -25,7 +25,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
+
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/server_finishes_request.cc b/test/core/end2end/tests/server_finishes_request.cc
index 743b3ae..f135851 100644
--- a/test/core/end2end/tests/server_finishes_request.cc
+++ b/test/core/end2end/tests/server_finishes_request.cc
@@ -26,7 +26,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/gpr/string.h"
 #include "test/core/end2end/cq_verifier.h"
 
diff --git a/test/core/end2end/tests/shutdown_finishes_calls.cc b/test/core/end2end/tests/shutdown_finishes_calls.cc
index fce23f3..2e19e05 100644
--- a/test/core/end2end/tests/shutdown_finishes_calls.cc
+++ b/test/core/end2end/tests/shutdown_finishes_calls.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/shutdown_finishes_tags.cc b/test/core/end2end/tests/shutdown_finishes_tags.cc
index de64eba..d160647 100644
--- a/test/core/end2end/tests/shutdown_finishes_tags.cc
+++ b/test/core/end2end/tests/shutdown_finishes_tags.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/simple_cacheable_request.cc b/test/core/end2end/tests/simple_cacheable_request.cc
index d8034dc..b4732ae 100644
--- a/test/core/end2end/tests/simple_cacheable_request.cc
+++ b/test/core/end2end/tests/simple_cacheable_request.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 enum { TIMEOUT = 200000 };
diff --git a/test/core/end2end/tests/simple_delayed_request.cc b/test/core/end2end/tests/simple_delayed_request.cc
index 0ad224f..54517fb 100644
--- a/test/core/end2end/tests/simple_delayed_request.cc
+++ b/test/core/end2end/tests/simple_delayed_request.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/simple_metadata.cc b/test/core/end2end/tests/simple_metadata.cc
index 1a74116..5911834 100644
--- a/test/core/end2end/tests/simple_metadata.cc
+++ b/test/core/end2end/tests/simple_metadata.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/simple_request.cc b/test/core/end2end/tests/simple_request.cc
index ae93f79..6ec4a14 100644
--- a/test/core/end2end/tests/simple_request.cc
+++ b/test/core/end2end/tests/simple_request.cc
@@ -26,7 +26,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/debug/stats.h"
 #include "src/core/lib/gpr/string.h"
 #include "test/core/end2end/cq_verifier.h"
diff --git a/test/core/end2end/tests/stream_compression_compressed_payload.cc b/test/core/end2end/tests/stream_compression_compressed_payload.cc
index 9a38444..d19a60f 100644
--- a/test/core/end2end/tests/stream_compression_compressed_payload.cc
+++ b/test/core/end2end/tests/stream_compression_compressed_payload.cc
@@ -28,7 +28,6 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/surface/call.h"
diff --git a/test/core/end2end/tests/stream_compression_payload.cc b/test/core/end2end/tests/stream_compression_payload.cc
index 9a27957..6abb3bb 100644
--- a/test/core/end2end/tests/stream_compression_payload.cc
+++ b/test/core/end2end/tests/stream_compression_payload.cc
@@ -26,7 +26,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/surface/call.h"
 #include "test/core/end2end/cq_verifier.h"
diff --git a/test/core/end2end/tests/stream_compression_ping_pong_streaming.cc b/test/core/end2end/tests/stream_compression_ping_pong_streaming.cc
index 4dc306b..8242c2c 100644
--- a/test/core/end2end/tests/stream_compression_ping_pong_streaming.cc
+++ b/test/core/end2end/tests/stream_compression_ping_pong_streaming.cc
@@ -26,7 +26,7 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
+
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/surface/call.h"
 #include "test/core/end2end/cq_verifier.h"
diff --git a/test/core/end2end/tests/streaming_error_response.cc b/test/core/end2end/tests/streaming_error_response.cc
index 6ad1cec..167530a 100644
--- a/test/core/end2end/tests/streaming_error_response.cc
+++ b/test/core/end2end/tests/streaming_error_response.cc
@@ -28,7 +28,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/trailing_metadata.cc b/test/core/end2end/tests/trailing_metadata.cc
index afc56c8..150c1cb 100644
--- a/test/core/end2end/tests/trailing_metadata.cc
+++ b/test/core/end2end/tests/trailing_metadata.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/workaround_cronet_compression.cc b/test/core/end2end/tests/workaround_cronet_compression.cc
index 97ab814..e801e2d 100644
--- a/test/core/end2end/tests/workaround_cronet_compression.cc
+++ b/test/core/end2end/tests/workaround_cronet_compression.cc
@@ -28,7 +28,6 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/surface/call.h"
diff --git a/test/core/end2end/tests/write_buffering.cc b/test/core/end2end/tests/write_buffering.cc
index 40821dd..7f3d1ab 100644
--- a/test/core/end2end/tests/write_buffering.cc
+++ b/test/core/end2end/tests/write_buffering.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }
diff --git a/test/core/end2end/tests/write_buffering_at_end.cc b/test/core/end2end/tests/write_buffering_at_end.cc
index 1b9dc96..a1fbfef 100644
--- a/test/core/end2end/tests/write_buffering_at_end.cc
+++ b/test/core/end2end/tests/write_buffering_at_end.cc
@@ -25,7 +25,6 @@
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include <grpc/support/useful.h>
 #include "test/core/end2end/cq_verifier.h"
 
 static void* tag(intptr_t t) { return (void*)t; }