DevTools: simplify the async instrumentation harness.

third_party/WebKit/Source/core/dom/MutationObserver.cpp

 /*
  * Copyright (C) 2011 Google 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.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 51 matching lines @@
     : m_callback(callback)
     , m_priority(s_observerPriority++)
 {
 }
 
 MutationObserver::~MutationObserver()
 {
 #if !ENABLE(OILPAN)
     ASSERT(m_registrations.isEmpty());
 #endif
-    if (!m_records.isEmpty())
-        InspectorInstrumentation::didClearAllMutationRecords(m_callback->getExecutionContext(), this);
+    cancelInspectorAsyncTasks();
 }
 
 void MutationObserver::observe(Node* node, const MutationObserverInit& observerInit, ExceptionState& exceptionState)
 {
     ASSERT(node);
 
     MutationObserverOptions options = 0;
 
     if (observerInit.hasAttributeOldValue() && observerInit.attributeOldValue())
         options |= AttributeOldValue;
@@ skipping 42 matching lines @@
         exceptionState.throwTypeError("The options object must set at least one of 'attributes', 'characterData', or 'childList' to true.");
         return;
     }
 
     node->registerMutationObserver(*this, options, attributeFilter);
 }
 
 MutationRecordVector MutationObserver::takeRecords()
 {
     MutationRecordVector records;
+    cancelInspectorAsyncTasks();
     records.swap(m_records);
-    InspectorInstrumentation::didClearAllMutationRecords(m_callback->getExecutionContext(), this);
     return records;
 }
 
 void MutationObserver::disconnect()
 {
+    cancelInspectorAsyncTasks();
     m_records.clear();
-    InspectorInstrumentation::didClearAllMutationRecords(m_callback->getExecutionContext(), this);
     MutationObserverRegistrationSet registrations(m_registrations);
     for (auto& registration : registrations) {
         // The registration may be already unregistered while iteration.
         // Only call unregister if it is still in the original set.
         if (m_registrations.contains(registration))
             registration->unregister();
     }
     ASSERT(m_registrations.isEmpty());
 }
 
@@ skipping 27 matching lines @@
         Microtask::enqueueMicrotask(WTF::bind(&MutationObserver::deliverMutations));
 
     activeMutationObservers().add(observer);
 }
 
 void MutationObserver::enqueueMutationRecord(RawPtr<MutationRecord> mutation)
 {
     ASSERT(isMainThread());
     m_records.append(mutation);
     activateObserver(this);
-    InspectorInstrumentation::didEnqueueMutationRecord(m_callback->getExecutionContext(), this);
+    InspectorInstrumentation::asyncTaskScheduled(m_callback->getExecutionContext(), mutation->type(), mutation);
 }
 
 void MutationObserver::setHasTransientRegistration()
 {
     ASSERT(isMainThread());
     activateObserver(this);
 }
 
 HeapHashSet<Member<Node>> MutationObserver::getObservedNodes() const
 {
     HeapHashSet<Member<Node>> observedNodes;
     for (const auto& registration : m_registrations)
         registration->addRegistrationNodesToSet(observedNodes);
     return observedNodes;
 }
 
 bool MutationObserver::shouldBeSuspended() const
 {
     return m_callback->getExecutionContext() && m_callback->getExecutionContext()->activeDOMObjectsAreSuspended();
 }
 
+void MutationObserver::cancelInspectorAsyncTasks()
+{
+    for (auto& record : m_records)
+        InspectorInstrumentation::asyncTaskCanceled(m_callback->getExecutionContext(), record);
+}
+
 void MutationObserver::deliver()
 {
     ASSERT(!shouldBeSuspended());
 
     // Calling clearTransientRegistrations() can modify m_registrations, so it's necessary
     // to make a copy of the transient registrations before operating on them.
     HeapVector<Member<MutationObserverRegistration>, 1> transientRegistrations;
     for (auto& registration : m_registrations) {
         if (registration->hasTransientRegistrations())
             transientRegistrations.append(registration);
     }
     for (size_t i = 0; i < transientRegistrations.size(); ++i)
         transientRegistrations[i]->clearTransientRegistrations();
 
     if (m_records.isEmpty())
         return;
 
     MutationRecordVector records;
     records.swap(m_records);
 
-    InspectorInstrumentation::willDeliverMutationRecords(m_callback->getExecutionContext(), this);
+    // Report the first (earliest) stack as the async cause.
+    InspectorInstrumentation::AsyncTask asyncTask(m_callback->getExecutionContext(), records.first());
     m_callback->call(records, this);
-    InspectorInstrumentation::didDeliverMutationRecords(m_callback->getExecutionContext());
 }
 
 void MutationObserver::resumeSuspendedObservers()
 {
     ASSERT(isMainThread());
     if (suspendedMutationObservers().isEmpty())
         return;
 
     MutationObserverVector suspended;
     copyToVector(suspendedMutationObservers(), suspended);
@@ skipping 22 matching lines @@
 
 DEFINE_TRACE(MutationObserver)
 {
     visitor->trace(m_callback);
     visitor->trace(m_records);
     visitor->trace(m_registrations);
     visitor->trace(m_callback);
 }
 
 } // namespace blink