[EventEngine] Enable work stealing thread pool in debug builds (#33333)

bazel/experiments.bzl

@@ -18,6 +18,9 @@
 
 EXPERIMENTS = {
     "dbg": {
+        "core_end2end_test": [
+            "work_stealing",
+        ],
     },
     "off": {
         "census_test": [
@@ -28,7 +31,6 @@ EXPERIMENTS = {
             "event_engine_listener",
             "promise_based_client_call",
             "promise_based_server_call",
-            "work_stealing",
         ],
         "cpp_end2end_test": [
             "promise_based_server_call",

src/core/lib/experiments/experiments.cc

@@ -86,6 +86,11 @@ const char* const description_canary_client_privacy =
 const char* const additional_constraints_canary_client_privacy = "{}";
 const char* const description_server_privacy = "If set, server privacy";
 const char* const additional_constraints_server_privacy = "{}";
+#ifdef NDEBUG
+const bool kDefaultForDebugOnly = false;
+#else
+const bool kDefaultForDebugOnly = true;
+#endif
 }  // namespace
 
 namespace grpc_core {
@@ -125,7 +130,7 @@ const ExperimentMetadata g_experiment_metadata[] = {
     {"event_engine_dns", description_event_engine_dns,
      additional_constraints_event_engine_dns, false, false},
     {"work_stealing", description_work_stealing,
-     additional_constraints_work_stealing, false, false},
+     additional_constraints_work_stealing, kDefaultForDebugOnly, false},
     {"client_privacy", description_client_privacy,
      additional_constraints_client_privacy, false, false},
     {"canary_client_privacy", description_canary_client_privacy,

src/core/lib/experiments/experiments.h

@@ -73,7 +73,16 @@ inline bool IsEventEngineListenerEnabled() { return false; }
 inline bool IsScheduleCancellationOverWriteEnabled() { return false; }
 inline bool IsTraceRecordCallopsEnabled() { return false; }
 inline bool IsEventEngineDnsEnabled() { return false; }
-inline bool IsWorkStealingEnabled() { return false; }
+#ifndef NDEBUG
+#define GRPC_EXPERIMENT_IS_INCLUDED_WORK_STEALING
+#endif
+inline bool IsWorkStealingEnabled() {
+#ifdef NDEBUG
+  return false;
+#else
+  return true;
+#endif
+}
 inline bool IsClientPrivacyEnabled() { return false; }
 inline bool IsCanaryClientPrivacyEnabled() { return false; }
 inline bool IsServerPrivacyEnabled() { return false; }

src/core/lib/experiments/rollouts.yaml

@@ -53,7 +53,7 @@
 - name: event_engine_dns
   default: false
 - name: work_stealing
-  default: false
+  default: debug
 - name: client_privacy
   default: false
 - name: canary_client_privacy