diff --git a/third_party/blink/renderer/bindings/core/v8/worker_or_worklet_script_controller.cc b/third_party/blink/renderer/bindings/core/v8/worker_or_worklet_script_controller.cc
index 26a0f26..7f25150 100644
--- a/third_party/blink/renderer/bindings/core/v8/worker_or_worklet_script_controller.cc
+++ b/third_party/blink/renderer/bindings/core/v8/worker_or_worklet_script_controller.cc
@@ -142,7 +142,7 @@
   script_state_->DissociateContext();
 }
 
-bool WorkerOrWorkletScriptController::Initialize(const KURL& url_for_debugger) {
+void WorkerOrWorkletScriptController::Initialize(const KURL& url_for_debugger) {
   v8::HandleScope handle_scope(isolate_);
 
   DCHECK(!IsContextInitialized());
@@ -154,8 +154,7 @@
       script_wrappable->GetWrapperTypeInfo();
   v8::Local<v8::FunctionTemplate> global_interface_template =
       wrapper_type_info->DomTemplate(isolate_, *world_);
-  if (global_interface_template.IsEmpty())
-    return false;
+  DCHECK(!global_interface_template.IsEmpty());
   v8::Local<v8::ObjectTemplate> global_template =
       global_interface_template->InstanceTemplate();
   v8::Local<v8::Context> context;
@@ -174,8 +173,7 @@
                                v8::DeserializeInternalFieldsCallback(),
                                agent->event_loop()->microtask_queue());
   }
-  if (context.IsEmpty())
-    return false;
+  DCHECK(!context.IsEmpty());
 
   script_state_ = MakeGarbageCollected<ScriptState>(context, world_);
 
@@ -269,8 +267,6 @@
     // call this here.
     PrepareForEvaluation();
   }
-
-  return true;
 }
 
 void WorkerOrWorkletScriptController::PrepareForEvaluation() {
diff --git a/third_party/blink/renderer/bindings/core/v8/worker_or_worklet_script_controller.h b/third_party/blink/renderer/bindings/core/v8/worker_or_worklet_script_controller.h
index fd3f5a3a..b67f3f8d 100644
--- a/third_party/blink/renderer/bindings/core/v8/worker_or_worklet_script_controller.h
+++ b/third_party/blink/renderer/bindings/core/v8/worker_or_worklet_script_controller.h
@@ -73,7 +73,7 @@
   // For main thread WorkletGlobalScope, WorkerOrWorkletGlobalScope::Name() is
   // used for setting DOMWrapperWorld's human readable name.
   // This should be called only once.
-  bool Initialize(const KURL& url_for_debugger);
+  void Initialize(const KURL& url_for_debugger);
 
   // Prepares for script evaluation. This must be called after Initialize()
   // before Evaluate().
diff --git a/third_party/blink/renderer/core/layout/custom/layout_worklet_global_scope.cc b/third_party/blink/renderer/core/layout/custom/layout_worklet_global_scope.cc
index 5920b3d..1eb519d 100644
--- a/third_party/blink/renderer/core/layout/custom/layout_worklet_global_scope.cc
+++ b/third_party/blink/renderer/core/layout/custom/layout_worklet_global_scope.cc
@@ -32,7 +32,6 @@
   auto* global_scope = MakeGarbageCollected<LayoutWorkletGlobalScope>(
       frame, std::move(creation_params), reporting_proxy,
       pending_layout_registry);
-  // TODO(bashi): Handle a case where the script controller fails to initialize.
   global_scope->ScriptController()->Initialize(NullURL());
   MainThreadDebugger::Instance()->ContextCreated(
       global_scope->ScriptController()->GetScriptState(),
diff --git a/third_party/blink/renderer/core/loader/modulescript/module_script_loader_test.cc b/third_party/blink/renderer/core/loader/modulescript/module_script_loader_test.cc
index f8e6a18d..9e3ca31 100644
--- a/third_party/blink/renderer/core/loader/modulescript/module_script_loader_test.cc
+++ b/third_party/blink/renderer/core/loader/modulescript/module_script_loader_test.cc
@@ -194,7 +194,7 @@
       MakeGarbageCollected<WorkletModuleResponsesMap>());
   global_scope_ = MakeGarbageCollected<WorkletGlobalScope>(
       std::move(creation_params), *reporting_proxy_, &GetFrame());
-  ASSERT_TRUE(global_scope_->ScriptController()->Initialize(NullURL()));
+  global_scope_->ScriptController()->Initialize(NullURL());
   modulator_ = MakeGarbageCollected<ModuleScriptLoaderTestModulator>(
       global_scope_->ScriptController()->GetScriptState());
 }
diff --git a/third_party/blink/renderer/core/workers/worker_reporting_proxy.h b/third_party/blink/renderer/core/workers/worker_reporting_proxy.h
index dffa510..1fb08610 100644
--- a/third_party/blink/renderer/core/workers/worker_reporting_proxy.h
+++ b/third_party/blink/renderer/core/workers/worker_reporting_proxy.h
@@ -69,13 +69,10 @@
   virtual void DidCreateWorkerGlobalScope(WorkerOrWorkletGlobalScope*) {}
 
   // Invoked when the WorkerGlobalScope is initialized on
-  // WorkerThread::InitializeOnWorkerThread.
+  // WorkerThread::InitializeOnWorkerThread. This is synchronously called after
+  // WillInitializeWorkerContext().
   virtual void DidInitializeWorkerContext() {}
 
-  // Invoked when the WorkerGlobalScope initialization failed on
-  // WorkerThread::InitializeOnWorkerThread.
-  virtual void DidFailToInitializeWorkerContext() {}
-
   // Invoked when the worker's main script is loaded on
   // WorkerThread::InitializeOnWorkerThread(). Only invoked when the script was
   // loaded on the worker thread, i.e., via InstalledScriptsManager rather than
diff --git a/third_party/blink/renderer/core/workers/worker_thread.cc b/third_party/blink/renderer/core/workers/worker_thread.cc
index 6a2463a..0da8aa29d 100644
--- a/third_party/blink/renderer/core/workers/worker_thread.cc
+++ b/third_party/blink/renderer/core/workers/worker_thread.cc
@@ -543,18 +543,11 @@
             WorkerThreadDebugger::From(GetIsolate()))
       debugger->WorkerThreadCreated(this);
 
-    if (GlobalScope()->ScriptController()->Initialize(url_for_debugger)) {
-      worker_reporting_proxy_.DidInitializeWorkerContext();
-      v8::HandleScope handle_scope(GetIsolate());
-      Platform::Current()->WorkerContextCreated(
-          GlobalScope()->ScriptController()->GetContext());
-    } else {
-      // TODO(nhiroki): Handle a case where the script controller fails to
-      // initialize the context. Specifically, we need to terminate this worker
-      // thread from the the parent thread. Currently we only record trace
-      // event.
-      worker_reporting_proxy_.DidFailToInitializeWorkerContext();
-    }
+    GlobalScope()->ScriptController()->Initialize(url_for_debugger);
+    worker_reporting_proxy_.DidInitializeWorkerContext();
+    v8::HandleScope handle_scope(GetIsolate());
+    Platform::Current()->WorkerContextCreated(
+        GlobalScope()->ScriptController()->GetContext());
 
     inspector_task_runner_->InitIsolate(GetIsolate());
     SetThreadState(ThreadState::kRunning);
diff --git a/third_party/blink/renderer/modules/csspaint/paint_worklet_global_scope.cc b/third_party/blink/renderer/modules/csspaint/paint_worklet_global_scope.cc
index 065a744..347872f 100644
--- a/third_party/blink/renderer/modules/csspaint/paint_worklet_global_scope.cc
+++ b/third_party/blink/renderer/modules/csspaint/paint_worklet_global_scope.cc
@@ -103,7 +103,6 @@
   auto* global_scope = MakeGarbageCollected<PaintWorkletGlobalScope>(
       frame, std::move(creation_params), reporting_proxy,
       pending_generator_registry);
-  // TODO(bashi): Handle a case where the script controller fails to initialize.
   global_scope->ScriptController()->Initialize(NullURL());
   MainThreadDebugger::Instance()->ContextCreated(
       global_scope->ScriptController()->GetScriptState(),
diff --git a/third_party/blink/renderer/modules/service_worker/service_worker_global_scope_proxy.cc b/third_party/blink/renderer/modules/service_worker/service_worker_global_scope_proxy.cc
index c71a6691..384323d 100644
--- a/third_party/blink/renderer/modules/service_worker/service_worker_global_scope_proxy.cc
+++ b/third_party/blink/renderer/modules/service_worker/service_worker_global_scope_proxy.cc
@@ -647,9 +647,8 @@
 
 void ServiceWorkerGlobalScopeProxy::WillInitializeWorkerContext() {
   DCHECK_CALLED_ON_VALID_THREAD(worker_thread_checker_);
-  TRACE_EVENT_ASYNC_BEGIN0(
-      "ServiceWorker", "ServiceWorkerGlobalScopeProxy::InitializeWorkerContext",
-      this);
+  TRACE_EVENT_BEGIN0("ServiceWorker",
+                     "ServiceWorkerGlobalScopeProxy::InitializeWorkerContext");
 }
 
 void ServiceWorkerGlobalScopeProxy::DidCreateWorkerGlobalScope(
@@ -674,16 +673,8 @@
       WorkerGlobalScope()->ScriptController()->GetScriptState());
   Client().DidInitializeWorkerContext(
       WorkerGlobalScope()->ScriptController()->GetContext());
-  TRACE_EVENT_ASYNC_END1(
-      "ServiceWorker", "ServiceWorkerGlobalScopeProxy::InitializeWorkerContext",
-      this, "success", true);
-}
-
-void ServiceWorkerGlobalScopeProxy::DidFailToInitializeWorkerContext() {
-  DCHECK_CALLED_ON_VALID_THREAD(worker_thread_checker_);
-  TRACE_EVENT_ASYNC_END1(
-      "ServiceWorker", "ServiceWorkerGlobalScopeProxy::InitializeWorkerContext",
-      this, "success", false);
+  TRACE_EVENT_END0("ServiceWorker",
+                   "ServiceWorkerGlobalScopeProxy::InitializeWorkerContext");
 }
 
 void ServiceWorkerGlobalScopeProxy::DidLoadClassicScript() {
diff --git a/third_party/blink/renderer/modules/service_worker/service_worker_global_scope_proxy.h b/third_party/blink/renderer/modules/service_worker/service_worker_global_scope_proxy.h
index fa37add7..8079939 100644
--- a/third_party/blink/renderer/modules/service_worker/service_worker_global_scope_proxy.h
+++ b/third_party/blink/renderer/modules/service_worker/service_worker_global_scope_proxy.h
@@ -165,7 +165,6 @@
   void WillInitializeWorkerContext() override;
   void DidCreateWorkerGlobalScope(WorkerOrWorkletGlobalScope*) override;
   void DidInitializeWorkerContext() override;
-  void DidFailToInitializeWorkerContext() override;
   void DidLoadClassicScript() override;
   void DidFailToLoadClassicScript() override;
   void DidFetchScript() override;