diff --git a/media/mojo/clients/mojo_codec_factory.cc b/media/mojo/clients/mojo_codec_factory.cc
index 0dfe148f7bbea..3cc739df460c4 100644
--- a/media/mojo/clients/mojo_codec_factory.cc
+++ b/media/mojo/clients/mojo_codec_factory.cc
@@ -7,8 +7,10 @@
 #include <memory>
 #include <optional>
 
+#include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/notimplemented.h"
+#include "base/threading/platform_thread.h"
 #include "base/task/bind_post_task.h"
 #include "base/task/sequenced_task_runner.h"
 #include "media/base/decoder.h"
@@ -119,12 +121,20 @@ void MojoCodecFactory::NotifyDecoderSupportKnown(base::OnceClosure callback) {
 
 void MojoCodecFactory::NotifyEncoderSupportKnown(base::OnceClosure callback) {
   base::AutoLock lock(supported_profiles_lock_);
+  LOG(ERROR) << "POCTRACE NotifyEncoderSupportKnown tid="
+             << base::PlatformThread::CurrentId()
+             << " name=" << base::PlatformThread::GetName()
+             << " is_notified=" << encoder_support_notifier_.is_notified()
+             << " runner=" << base::SequencedTaskRunner::GetCurrentDefault().get();
   encoder_support_notifier_.Register(
       base::BindPostTaskToCurrentDefault(std::move(callback)));
 }
 
 void MojoCodecFactory::OnChannelTokenReady(const base::UnguessableToken& token,
                                            int32_t route_id) {
+  LOG(ERROR) << "POCTRACE OnChannelTokenReady tid="
+             << base::PlatformThread::CurrentId()
+             << " name=" << base::PlatformThread::GetName();
   base::AutoLock lock(supported_profiles_lock_);
   channel_token_ = token;
   route_id_ = route_id;
@@ -148,6 +158,10 @@ void MojoCodecFactory::Notifier::Register(base::OnceClosure callback) {
 
 void MojoCodecFactory::Notifier::Notify() {
   DCHECK(!is_notified_);
+  LOG(ERROR) << "POCTRACE Notifier::Notify tid="
+             << base::PlatformThread::CurrentId()
+             << " name=" << base::PlatformThread::GetName()
+             << " ncb=" << callbacks_.size();
   is_notified_ = true;
   while (!callbacks_.empty()) {
     std::move(callbacks_.back()).Run();
@@ -170,6 +184,9 @@ void MojoCodecFactory::OnGetSupportedDecoderConfigs() {
 }
 
 void MojoCodecFactory::OnEncoderSupportFailed() {
+  LOG(ERROR) << "POCTRACE OnEncoderSupportFailed tid="
+             << base::PlatformThread::CurrentId()
+             << " name=" << base::PlatformThread::GetName();
   base::AutoLock lock(supported_profiles_lock_);
   if (encoder_support_notifier_.is_notified()) {
     return;
@@ -180,6 +197,9 @@ void MojoCodecFactory::OnEncoderSupportFailed() {
 
 void MojoCodecFactory::OnGetVideoEncodeAcceleratorSupportedProfiles(
     const VideoEncodeAccelerator::SupportedProfiles& supported_profiles) {
+  LOG(ERROR) << "POCTRACE OnGetVEASupportedProfiles tid="
+             << base::PlatformThread::CurrentId()
+             << " name=" << base::PlatformThread::GetName();
   base::AutoLock lock(supported_profiles_lock_);
   supported_vea_profiles_ = supported_profiles;
   if (IsEncoderReady()) {
diff --git a/third_party/blink/renderer/platform/heap/heap_barrier_callback.h b/third_party/blink/renderer/platform/heap/heap_barrier_callback.h
index 54c8c24ecc12e..74fc51a4e686e 100644
--- a/third_party/blink/renderer/platform/heap/heap_barrier_callback.h
+++ b/third_party/blink/renderer/platform/heap/heap_barrier_callback.h
@@ -17,6 +17,8 @@
 #include "base/functional/callback_helpers.h"
 #include "base/notreached.h"
 #include "base/thread_annotations.h"
+#include "base/logging.h"
+#include "base/threading/platform_thread.h"
 #include "third_party/blink/renderer/platform/heap/collection_support/heap_vector.h"
 #include "third_party/blink/renderer/platform/heap/cross_thread_handle.h"
 
@@ -34,8 +36,22 @@ class BarrierCallbackInfo {
             MakeGarbageCollected<GCedHeapVector<Member<T>>>())),
         done_callback_(std::move(done_callback)) {
     results_.GetOnCreationThread()->reserve(num_callbacks);
+    creation_tid_ = base::PlatformThread::CurrentId();
   }
 
+  ~BarrierCallbackInfo() {
+    auto tid = base::PlatformThread::CurrentId();
+    if (tid != creation_tid_) {
+      LOG(ERROR) << "POCTRACE BarrierCallbackInfo DTOR tid=" << tid
+                 << " name=" << base::PlatformThread::GetName()
+                 << " ctor_tid=" << creation_tid_
+                 << " done_cb_live=" << !!done_callback_
+                 << " *** OFF-THREAD ***";
+    }
+  }
+
+  base::PlatformThreadId creation_tid_;
+
   void Run(T* t) {
     DCHECK_NE(num_callbacks_left_, 0U);
     results_.GetOnCreationThread()->push_back(std::move(t));