Add {CancelableTaskManager} to handle {Cancelable} concurrent tasks.

src/heap/scavenge-job.cc

Index: src/heap/scavenge-job.cc
diff --git a/src/heap/scavenge-job.cc b/src/heap/scavenge-job.cc
index faf90face5152ef99594654045362ded5e4dc63e..52ba97a9c7bab9f64769f031e328903d95a271f0 100644
--- a/src/heap/scavenge-job.cc
+++ b/src/heap/scavenge-job.cc
@@ -17,7 +17,7 @@ namespace internal {
 const double ScavengeJob::kMaxAllocationLimitAsFractionOfNewSpace = 0.8;
 
 void ScavengeJob::IdleTask::RunInternal(double deadline_in_seconds) {
-  Heap* heap = isolate_->heap();
+  Heap* heap = isolate()->heap();
   double deadline_in_ms =
       deadline_in_seconds *
       static_cast<double>(base::Time::kMillisecondsPerSecond);