[heap] Use RAIL mode for initial heap sizing

src/heap/incremental-marking-job.cc

Index: src/heap/incremental-marking-job.cc
diff --git a/src/heap/incremental-marking-job.cc b/src/heap/incremental-marking-job.cc
index 393b9cce7eeace05b893679d448bfb54490261df..e441261c84bee72cdda12b8e50a4f56bd48c3345 100644
--- a/src/heap/incremental-marking-job.cc
+++ b/src/heap/incremental-marking-job.cc
@@ -19,12 +19,11 @@ void IncrementalMarkingJob::Start(Heap* heap) {
   ScheduleTask(heap);
 }
 
-void IncrementalMarkingJob::NotifyTask() { task_pending_ = false; }
+void IncrementalMarkingJob::NotifyTask() { task_pending_.SetValue(false); }
 
 void IncrementalMarkingJob::ScheduleTask(Heap* heap) {
-  if (!task_pending_) {
+  if (task_pending_.TrySetValue(false, true)) {
     v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(heap->isolate());
-    task_pending_ = true;
     auto task = new Task(heap->isolate(), this);
     V8::GetCurrentPlatform()->CallOnForegroundThread(isolate, task);
   }