[heap] Use RAIL mode for initial heap sizing

src/heap/incremental-marking-job.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/incremental-marking-job.h"
 
 #include "src/base/platform/time.h"
 #include "src/heap/heap-inl.h"
 #include "src/heap/heap.h"
 #include "src/heap/incremental-marking.h"
 #include "src/isolate.h"
 #include "src/v8.h"
 
 namespace v8 {
 namespace internal {
 
 void IncrementalMarkingJob::Start(Heap* heap) {
   DCHECK(!heap->incremental_marking()->IsStopped());
   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);
   }
 }
 
 void IncrementalMarkingJob::Task::Step(Heap* heap) {
   const int kIncrementalMarkingDelayMs = 1;
   double deadline =
       heap->MonotonicallyIncreasingTimeInMs() + kIncrementalMarkingDelayMs;
   heap->incremental_marking()->AdvanceIncrementalMarking(
@@ skipping 18 matching lines @@
   if (!incremental_marking->IsStopped()) {
     Step(heap);
     if (!incremental_marking->IsStopped()) {
       job_->ScheduleTask(heap);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8