Don't use TLS for space iterators.

src/heap-profiler.h

 // Copyright 2009-2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 65 matching lines @@
   void DefineWrapperClass(
       uint16_t class_id, v8::HeapProfiler::WrapperInfoCallback callback);
 
   v8::RetainedObjectInfo* ExecuteWrapperClassCallback(uint16_t class_id,
                                                       Object** wrapper);
   INLINE(bool is_profiling()) {
     return snapshots_->is_tracking_objects();
   }
 
  private:
-  HeapProfiler();
+  explicit HeapProfiler(Heap* heap);
   ~HeapProfiler();
   HeapSnapshot* TakeSnapshotImpl(
       const char* name,
       int type,
       v8::ActivityControl* control,
       v8::HeapProfiler::ObjectNameResolver* resolver);
   HeapSnapshot* TakeSnapshotImpl(
       String* name,
       int type,
       v8::ActivityControl* control,
       v8::HeapProfiler::ObjectNameResolver* resolver);
   void ResetSnapshots();
 
   void StartHeapObjectsTrackingImpl();
   void StopHeapObjectsTrackingImpl();
   SnapshotObjectId PushHeapObjectsStatsImpl(OutputStream* stream);
 
+  Heap* heap() const { return snapshots_->heap(); }
+
   HeapSnapshotsCollection* snapshots_;
   unsigned next_snapshot_uid_;
   List<v8::HeapProfiler::WrapperInfoCallback> wrapper_callbacks_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_PROFILER_H_