POC for InspectorInstrumentation adding InspectorWebPerfAgent

third_party/WebKit/Source/core/timing/PerformanceBase.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 40 matching lines @@
 static const size_t defaultResourceTimingBufferSize = 150;
 static const size_t defaultFrameTimingBufferSize = 150;
 
 PerformanceBase::PerformanceBase(double timeOrigin)
     : m_frameTimingBufferSize(defaultFrameTimingBufferSize)
     , m_resourceTimingBufferSize(defaultResourceTimingBufferSize)
     , m_timeOrigin(timeOrigin)
     , m_userTiming(nullptr)
     , m_observerFilterOptions(PerformanceEntry::Invalid)
     , m_deliverObservationsTimer(this, &PerformanceBase::deliverObservationsTimerFired)
+    , m_inspectorInstrumentationEnabled(false)
 {
 }
 
 PerformanceBase::~PerformanceBase()
 {
 }
 
 const AtomicString& PerformanceBase::interfaceName() const
 {
     return EventTargetNames::Performance;
 }
 
 PerformanceTiming* PerformanceBase::timing() const
 {
     return nullptr;
 }
 
+void PerformanceBase::enableInspectorInstrumentation() const
+{
+}
+
 PerformanceEntryVector PerformanceBase::getEntries() const
 {
     PerformanceEntryVector entries;
 
     entries.appendVector(m_resourceTimingBuffer);
     entries.appendVector(m_frameTimingBuffer);
 
     if (m_userTiming) {
         entries.appendVector(m_userTiming->getMarks());
         entries.appendVector(m_userTiming->getMeasures());
@@ skipping 261 matching lines @@
 {
     if (!m_userTiming)
         m_userTiming = UserTiming::create(*this);
     m_userTiming->clearMeasures(measureName);
 }
 
 void PerformanceBase::registerPerformanceObserver(PerformanceObserver& observer)
 {
     m_observerFilterOptions |= observer.filterOptions();
     m_observers.add(&observer);
+
+    // If this is the first long task observer then enable tracking of LongTaskTiming.
+    if (!m_inspectorInstrumentationEnabled
+        && hasObserverFor(PerformanceEntry::Mark)) { // PerformanceEntry::LongTask
+        fprintf(stderr, "\n^^^On observe(): enableInspectorInstrumentation");
+        enableInspectorInstrumentation();
+        m_inspectorInstrumentationEnabled = true;
+    } else {
+        fprintf(stderr, "\n^^^On observe(): NOT enableInspectorInstrumentation");
+    }
 }
 
 void PerformanceBase::unregisterPerformanceObserver(PerformanceObserver& oldObserver)
 {
     ASSERT(isMainThread());
     // Deliver any pending observations on this observer before unregistering.
     if (m_activeObservers.contains(&oldObserver) && !oldObserver.shouldBeSuspended()) {
         oldObserver.deliver();
         m_activeObservers.remove(&oldObserver);
     }
     m_observers.remove(&oldObserver);
     updatePerformanceObserverFilterOptions();
+
+    if (m_inspectorInstrumentationEnabled
+        && !hasObserverFor(PerformanceEntry::Mark)) {  // PerformanceEntry::LongTask
+        //disableInspectorInstrumentation();
+    }
 }
 
 void PerformanceBase::updatePerformanceObserverFilterOptions()
 {
     m_observerFilterOptions = PerformanceEntry::Invalid;
     for (const auto& observer : m_observers) {
         m_observerFilterOptions |= observer->filterOptions();
     }
 }
 
@@ skipping 74 matching lines @@
     visitor->trace(m_frameTimingBuffer);
     visitor->trace(m_resourceTimingBuffer);
     visitor->trace(m_userTiming);
     visitor->trace(m_observers);
     visitor->trace(m_activeObservers);
     visitor->trace(m_suspendedObservers);
     EventTargetWithInlineData::trace(visitor);
 }
 
 } // namespace blink