[wrapper-tracing] Add heap snapshot generator infrastructure

third_party/WebKit/Source/bindings/core/v8/V8Initializer.cpp

 /*
  * Copyright (C) 2009 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 399 matching lines @@
   isolate->SetAllowCodeGenerationFromStringsCallback(
       codeGenerationCheckCallbackInMainThread);
 
   if (RuntimeEnabledFeatures::v8IdleTasksEnabled()) {
     V8PerIsolateData::enableIdleTasks(
         isolate, WTF::makeUnique<V8IdleTaskRunner>(scheduler));
   }
 
   isolate->SetPromiseRejectCallback(promiseRejectHandlerInMainThread);
 
-  if (v8::HeapProfiler* profiler = isolate->GetHeapProfiler())
+  if (v8::HeapProfiler* profiler = isolate->GetHeapProfiler()) {
     profiler->SetWrapperClassInfoProvider(
         WrapperTypeInfo::NodeClassId, &RetainedDOMInfo::createRetainedDOMInfo);
+    profiler->SetGetRetainerInfosCallback(&V8GCController::getRetainerInfos);
+  }
 
   ASSERT(ThreadState::mainThreadState());
   ThreadState::mainThreadState()->addInterruptor(
       WTF::makeUnique<V8IsolateInterruptor>(isolate));
   ThreadState::mainThreadState()->registerTraceDOMWrappers(
       isolate, V8GCController::traceDOMWrappers,
       ScriptWrappableVisitor::invalidateDeadObjectsInMarkingDeque,
       ScriptWrappableVisitor::performCleanup);
 
   V8PerIsolateData::from(isolate)->setThreadDebugger(
@@ skipping 83 matching lines @@
           v8::Isolate::kMessageLog);
   isolate->SetFatalErrorHandler(reportFatalErrorInWorker);
 
   uint32_t here;
   isolate->SetStackLimit(reinterpret_cast<uintptr_t>(&here) -
                          kWorkerMaxStackSize);
   isolate->SetPromiseRejectCallback(promiseRejectHandlerInWorker);
 }
 
 }  // namespace blink