Re-enable parallel pointer updates.

src/heap/mark-compact.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/mark-compact.h"
 
 #include "src/base/atomicops.h"
 #include "src/base/bits.h"
 #include "src/base/sys-info.h"
 #include "src/code-stubs.h"
@@ skipping 3567 matching lines @@
 
 int NumberOfPointerUpdateTasks(int pages) {
   if (!FLAG_parallel_pointer_update) return 1;
   const int kMaxTasks = 4;
   const int kPagesPerTask = 4;
   return Min(kMaxTasks, (pages + kPagesPerTask - 1) / kPagesPerTask);
 }
 
 template <PointerDirection direction>
 void UpdatePointersInParallel(Heap* heap) {
-  PageParallelJob<PointerUpdateJobTraits<direction> > job(
-      heap, heap->isolate()->cancelable_task_manager());
+  PageParallelJob<PointerUpdateJobTraits<direction> >* job =
+      new PageParallelJob<PointerUpdateJobTraits<direction> >(
+          heap, heap->isolate()->cancelable_task_manager());
   RememberedSet<direction>::IterateMemoryChunks(
-      heap, [&job](MemoryChunk* chunk) { job.AddPage(chunk, 0); });
+      heap, [job](MemoryChunk* chunk) { job->AddPage(chunk, 0); });
   PointersUpdatingVisitor visitor(heap);
-  int num_pages = job.NumberOfPages();
+  int num_pages = job->NumberOfPages();
   int num_tasks = NumberOfPointerUpdateTasks(num_pages);
-  job.Run(num_tasks, [&visitor](int i) { return &visitor; });
+  job->Run(num_tasks, [&visitor](int i) { return &visitor; });
+  delete job;
 }
 
 void MarkCompactCollector::UpdatePointersAfterEvacuation() {
   GCTracer::Scope gc_scope(heap()->tracer(),
                            GCTracer::Scope::MC_EVACUATE_UPDATE_POINTERS);
 
   PointersUpdatingVisitor updating_visitor(heap());
 
   {
     GCTracer::Scope gc_scope(
@@ skipping 271 matching lines @@
     MarkBit mark_bit = Marking::MarkBitFrom(host);
     if (Marking::IsBlack(mark_bit)) {
       RelocInfo rinfo(isolate(), pc, RelocInfo::CODE_TARGET, 0, host);
       RecordRelocSlot(host, &rinfo, target);
     }
   }
 }
 
 }  // namespace internal
 }  // namespace v8