diff --git a/include/libplatform/v8-tracing.h b/include/libplatform/v8-tracing.h
index 12489327c5..6039a9c520 100644
--- a/include/libplatform/v8-tracing.h
+++ b/include/libplatform/v8-tracing.h
@@ -282,12 +282,12 @@ class V8_PLATFORM_EXPORT TracingController
                                 const char* name, uint64_t handle) override;
 
   static const char* GetCategoryGroupName(const uint8_t* category_enabled_flag);
-#endif  // !defined(V8_USE_PERFETTO)
 
   void AddTraceStateObserver(
       v8::TracingController::TraceStateObserver* observer) override;
   void RemoveTraceStateObserver(
       v8::TracingController::TraceStateObserver* observer) override;
+#endif  // !defined(V8_USE_PERFETTO)
 
   void StartTracing(TraceConfig* trace_config);
   void StopTracing();
@@ -307,7 +307,6 @@ class V8_PLATFORM_EXPORT TracingController
   std::unique_ptr<base::Mutex> mutex_;
   std::unique_ptr<TraceConfig> trace_config_;
   std::atomic_bool recording_{false};
-  std::unordered_set<v8::TracingController::TraceStateObserver*> observers_;
 
 #if defined(V8_USE_PERFETTO)
   std::ostream* output_stream_ = nullptr;
@@ -316,6 +315,7 @@ class V8_PLATFORM_EXPORT TracingController
   TraceEventListener* listener_for_testing_ = nullptr;
   std::unique_ptr<perfetto::TracingSession> tracing_session_;
 #else   // !defined(V8_USE_PERFETTO)
+  std::unordered_set<v8::TracingController::TraceStateObserver*> observers_;
   std::unique_ptr<TraceBuffer> trace_buffer_;
 #endif  // !defined(V8_USE_PERFETTO)
 
diff --git a/include/v8-platform.h b/include/v8-platform.h
index 32a82f881e..32898e7ef9 100644
--- a/include/v8-platform.h
+++ b/include/v8-platform.h
@@ -285,6 +285,8 @@ class ConvertableToTraceFormat {
  * V8 Tracing controller.
  *
  * Can be implemented by an embedder to record trace events from V8.
+ *
+ * Will become obsolete in Perfetto SDK build (v8_use_perfetto = true).
  */
 class TracingController {
  public:
@@ -348,10 +350,16 @@ class TracingController {
     virtual void OnTraceDisabled() = 0;
   };
 
-  /** Adds tracing state change observer. */
+  /**
+   * Adds tracing state change observer.
+   * Does nothing in Perfetto SDK build (v8_use_perfetto = true).
+   */
   virtual void AddTraceStateObserver(TraceStateObserver*) {}
 
-  /** Removes tracing state change observer. */
+  /**
+   * Removes tracing state change observer.
+   * Does nothing in Perfetto SDK build (v8_use_perfetto = true).
+   */
   virtual void RemoveTraceStateObserver(TraceStateObserver*) {}
 };
 
diff --git a/src/libplatform/tracing/tracing-controller.cc b/src/libplatform/tracing/tracing-controller.cc
index 55ca063184..0d235e8566 100644
--- a/src/libplatform/tracing/tracing-controller.cc
+++ b/src/libplatform/tracing/tracing-controller.cc
@@ -206,18 +206,19 @@ void TracingController::StartTracing(TraceConfig* trace_config) {
 #endif  // V8_USE_PERFETTO
 
   trace_config_.reset(trace_config);
+  recording_.store(true, std::memory_order_release);
+
+#ifndef V8_USE_PERFETTO
   std::unordered_set<v8::TracingController::TraceStateObserver*> observers_copy;
   {
     base::MutexGuard lock(mutex_.get());
-    recording_.store(true, std::memory_order_release);
-#ifndef V8_USE_PERFETTO
     UpdateCategoryGroupEnabledFlags();
-#endif
     observers_copy = observers_;
   }
   for (auto o : observers_copy) {
     o->OnTraceEnabled();
   }
+#endif
 }
 
 void TracingController::StopTracing() {
@@ -227,7 +228,6 @@ void TracingController::StopTracing() {
   }
 #ifndef V8_USE_PERFETTO
   UpdateCategoryGroupEnabledFlags();
-#endif
   std::unordered_set<v8::TracingController::TraceStateObserver*> observers_copy;
   {
     base::MutexGuard lock(mutex_.get());
@@ -236,6 +236,7 @@ void TracingController::StopTracing() {
   for (auto o : observers_copy) {
     o->OnTraceDisabled();
   }
+#endif
 
 #ifdef V8_USE_PERFETTO
   tracing_session_->StopBlocking();
@@ -341,7 +342,6 @@ const uint8_t* TracingController::GetCategoryGroupEnabled(
   }
   return category_group_enabled;
 }
-#endif  // !defined(V8_USE_PERFETTO)
 
 void TracingController::AddTraceStateObserver(
     v8::TracingController::TraceStateObserver* observer) {
@@ -360,6 +360,7 @@ void TracingController::RemoveTraceStateObserver(
   DCHECK(observers_.find(observer) != observers_.end());
   observers_.erase(observer);
 }
+#endif  // !defined(V8_USE_PERFETTO)
 
 }  // namespace tracing
 }  // namespace platform
diff --git a/src/profiler/tracing-cpu-profiler.cc b/src/profiler/tracing-cpu-profiler.cc
index d18ae09fb1..6d341282e4 100644
--- a/src/profiler/tracing-cpu-profiler.cc
+++ b/src/profiler/tracing-cpu-profiler.cc
@@ -14,16 +14,31 @@ namespace internal {
 
 TracingCpuProfilerImpl::TracingCpuProfilerImpl(Isolate* isolate)
     : isolate_(isolate), profiling_enabled_(false) {
+#if defined(V8_USE_PERFETTO)
+  TrackEvent::AddSessionObserver(this);
+  // Fire the observer if tracing is already in progress.
+  if (TrackEvent::IsEnabled()) OnStart({});
+#else
   V8::GetCurrentPlatform()->GetTracingController()->AddTraceStateObserver(this);
+#endif
 }
 
 TracingCpuProfilerImpl::~TracingCpuProfilerImpl() {
   StopProfiling();
+#if defined(V8_USE_PERFETTO)
+  TrackEvent::RemoveSessionObserver(this);
+#else
   V8::GetCurrentPlatform()->GetTracingController()->RemoveTraceStateObserver(
       this);
+#endif
 }
 
+#if defined(V8_USE_PERFETTO)
+void TracingCpuProfilerImpl::OnStart(
+    const perfetto::DataSourceBase::StartArgs&) {
+#else
 void TracingCpuProfilerImpl::OnTraceEnabled() {
+#endif
   bool enabled;
   TRACE_EVENT_CATEGORY_GROUP_ENABLED(
       TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"), &enabled);
@@ -36,7 +51,11 @@ void TracingCpuProfilerImpl::OnTraceEnabled() {
       this);
 }
 
+#if defined(V8_USE_PERFETTO)
+void TracingCpuProfilerImpl::OnStop(const perfetto::DataSourceBase::StopArgs&) {
+#else
 void TracingCpuProfilerImpl::OnTraceDisabled() {
+#endif
   base::MutexGuard lock(&mutex_);
   if (!profiling_enabled_) return;
   profiling_enabled_ = false;
diff --git a/src/profiler/tracing-cpu-profiler.h b/src/profiler/tracing-cpu-profiler.h
index 3adcaa63d7..0ccf7f0e5d 100644
--- a/src/profiler/tracing-cpu-profiler.h
+++ b/src/profiler/tracing-cpu-profiler.h
@@ -11,6 +11,7 @@
 #include "src/base/atomic-utils.h"
 #include "src/base/macros.h"
 #include "src/base/platform/mutex.h"
+#include "src/tracing/trace-event.h"
 
 namespace v8 {
 namespace internal {
@@ -19,16 +20,26 @@ class CpuProfiler;
 class Isolate;
 
 class TracingCpuProfilerImpl final
+#if defined(V8_USE_PERFETTO)
+    : public perfetto::TrackEventSessionObserver {
+#else
     : private v8::TracingController::TraceStateObserver {
+#endif
  public:
   explicit TracingCpuProfilerImpl(Isolate*);
   ~TracingCpuProfilerImpl() override;
   TracingCpuProfilerImpl(const TracingCpuProfilerImpl&) = delete;
   TracingCpuProfilerImpl& operator=(const TracingCpuProfilerImpl&) = delete;
 
+#if defined(V8_USE_PERFETTO)
+  // perfetto::TrackEventSessionObserver
+  void OnStart(const perfetto::DataSourceBase::StartArgs&) override;
+  void OnStop(const perfetto::DataSourceBase::StopArgs&) override;
+#else
   // v8::TracingController::TraceStateObserver
   void OnTraceEnabled() final;
   void OnTraceDisabled() final;
+#endif
 
  private:
   void StartProfiling();
diff --git a/src/tracing/tracing-category-observer.cc b/src/tracing/tracing-category-observer.cc
index 3debacb548..feee3807c6 100644
--- a/src/tracing/tracing-category-observer.cc
+++ b/src/tracing/tracing-category-observer.cc
@@ -16,17 +16,32 @@ TracingCategoryObserver* TracingCategoryObserver::instance_ = nullptr;
 
 void TracingCategoryObserver::SetUp() {
   TracingCategoryObserver::instance_ = new TracingCategoryObserver();
+#if defined(V8_USE_PERFETTO)
+  TrackEvent::AddSessionObserver(instance_);
+  // Fire the observer if tracing is already in progress.
+  if (TrackEvent::IsEnabled()) instance_->OnStart({});
+#else
   i::V8::GetCurrentPlatform()->GetTracingController()->AddTraceStateObserver(
       TracingCategoryObserver::instance_);
+#endif
 }
 
 void TracingCategoryObserver::TearDown() {
+#if defined(V8_USE_PERFETTO)
+  TrackEvent::RemoveSessionObserver(TracingCategoryObserver::instance_);
+#else
   i::V8::GetCurrentPlatform()->GetTracingController()->RemoveTraceStateObserver(
       TracingCategoryObserver::instance_);
+#endif
   delete TracingCategoryObserver::instance_;
 }
 
+#if defined(V8_USE_PERFETTO)
+void TracingCategoryObserver::OnStart(
+    const perfetto::DataSourceBase::StartArgs&) {
+#else
 void TracingCategoryObserver::OnTraceEnabled() {
+#endif
   bool enabled = false;
   TRACE_EVENT_CATEGORY_GROUP_ENABLED(
       TRACE_DISABLED_BY_DEFAULT("v8.runtime_stats"), &enabled);
@@ -66,7 +81,12 @@ void TracingCategoryObserver::OnTraceEnabled() {
   }
 }
 
+#if defined(V8_USE_PERFETTO)
+void TracingCategoryObserver::OnStop(
+    const perfetto::DataSourceBase::StopArgs&) {
+#else
 void TracingCategoryObserver::OnTraceDisabled() {
+#endif
   i::TracingFlags::runtime_stats.fetch_and(
       ~(ENABLED_BY_TRACING | ENABLED_BY_SAMPLING), std::memory_order_relaxed);
 
diff --git a/src/tracing/tracing-category-observer.h b/src/tracing/tracing-category-observer.h
index 858bf0bdf8..bf9687b5c2 100644
--- a/src/tracing/tracing-category-observer.h
+++ b/src/tracing/tracing-category-observer.h
@@ -6,11 +6,17 @@
 #define V8_TRACING_TRACING_CATEGORY_OBSERVER_H_
 
 #include "include/v8-platform.h"
+#include "src/tracing/trace-event.h"
 
 namespace v8 {
 namespace tracing {
 
-class TracingCategoryObserver : public TracingController::TraceStateObserver {
+class TracingCategoryObserver
+#if defined(V8_USE_PERFETTO)
+    : public perfetto::TrackEventSessionObserver {
+#else
+    : public TracingController::TraceStateObserver {
+#endif
  public:
   enum Mode {
     ENABLED_BY_NATIVE = 1 << 0,
@@ -21,9 +27,15 @@ class TracingCategoryObserver : public TracingController::TraceStateObserver {
   static void SetUp();
   static void TearDown();
 
+#if defined(V8_USE_PERFETTO)
+  // perfetto::TrackEventSessionObserver
+  void OnStart(const perfetto::DataSourceBase::StartArgs&) override;
+  void OnStop(const perfetto::DataSourceBase::StopArgs&) override;
+#else
   // v8::TracingController::TraceStateObserver
   void OnTraceEnabled() final;
   void OnTraceDisabled() final;
+#endif
 
  private:
   static TracingCategoryObserver* instance_;
diff --git a/test/unittests/libplatform/tracing-unittest.cc b/test/unittests/libplatform/tracing-unittest.cc
index 76f78af14c..d6cf31cb2a 100644
--- a/test/unittests/libplatform/tracing-unittest.cc
+++ b/test/unittests/libplatform/tracing-unittest.cc
@@ -389,6 +389,10 @@ TEST_F(PlatformTracingTest, TestTracingControllerMultipleArgsAndCopy) {
 }
 #endif  // !defined(V8_USE_PERFETTO)
 
+// In Perfetto build there are no TracingObservers. Instead the code relies on
+// TrackEventSessionObserver to track tracing sessions, which is tested
+// upstream.
+#if !defined(V8_USE_PERFETTO)
 namespace {
 
 class TraceStateObserverImpl : public TracingController::TraceStateObserver {
@@ -412,16 +416,11 @@ TEST_F(PlatformTracingTest, TracingObservers) {
   v8::platform::tracing::TracingController* tracing_controller = tracing.get();
   static_cast<v8::platform::DefaultPlatform*>(default_platform.get())
       ->SetTracingController(std::move(tracing));
-#ifdef V8_USE_PERFETTO
-  std::ostringstream sstream;
-  tracing_controller->InitializeForPerfetto(&sstream);
-#else
   MockTraceWriter* writer = new MockTraceWriter();
   v8::platform::tracing::TraceBuffer* ring_buffer =
       v8::platform::tracing::TraceBuffer::CreateTraceBufferRingBuffer(1,
                                                                       writer);
   tracing_controller->Initialize(ring_buffer);
-#endif
   v8::platform::tracing::TraceConfig* trace_config =
       new v8::platform::tracing::TraceConfig();
   trace_config->AddIncludedCategory("v8");
@@ -469,6 +468,7 @@ TEST_F(PlatformTracingTest, TracingObservers) {
 
   i::V8::SetPlatformForTesting(old_platform);
 }
+#endif  // !defined(V8_USE_PERFETTO)
 
 // With Perfetto the tracing controller doesn't observe events.
 #if !defined(V8_USE_PERFETTO)