[hpack_size] Un-parallelize tests (#31259)

* [hpack_size] Un-parallelize tests

* iwyu

test/core/end2end/tests/hpack_size.cc

@@ -20,15 +20,10 @@
 #include <stdio.h>
 #include <string.h>
 
-#include <algorithm>
-#include <memory>
 #include <string>
-#include <vector>
 
 #include "absl/strings/str_format.h"
-#include "absl/synchronization/notification.h"
 
-#include <grpc/event_engine/event_engine.h>
 #include <grpc/grpc.h>
 #include <grpc/impl/codegen/propagation_bits.h>
 #include <grpc/slice.h>
@@ -36,7 +31,6 @@
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
 
-#include "src/core/lib/event_engine/default_event_engine.h"
 #include "src/core/lib/gpr/useful.h"
 #include "src/core/lib/gprpp/time.h"
 #include "test/core/end2end/cq_verifier.h"
@@ -393,21 +387,11 @@ void hpack_size(grpc_end2end_test_config config) {
                                           1000, 32768, 4 * 1024 * 1024};
   size_t i, j;
 
-  auto event_engine = grpc_event_engine::experimental::GetDefaultEventEngine();
-  std::vector<std::shared_ptr<absl::Notification>> dones;
   for (i = 0; i < GPR_ARRAY_SIZE(interesting_sizes); i++) {
     for (j = 0; j < GPR_ARRAY_SIZE(interesting_sizes); j++) {
-      auto done = std::make_shared<absl::Notification>();
-      dones.push_back(done);
-      event_engine->Run([done, config, i, j] {
       test_size(config, interesting_sizes[i], interesting_sizes[j]);
-        done->Notify();
-      });
     }
   }
-  for (auto& done : dones) {
-    done->WaitForNotification();
-  }
 }
 
 void hpack_size_pre_init(void) {}