[heap] Concurrency support for heap book-keeping info

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index 54e7364d0f6463d723e660ec074c4dfd6646da04..936d840f4aac1617c13e673724e465e8f08b9f96 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -493,7 +493,7 @@ MemoryChunk* MemoryChunk::Initialize(Heap* heap, Address base, size_t size,
   chunk->skip_list_ = NULL;
   chunk->write_barrier_counter_ = kWriteBarrierCounterGranularity;
   chunk->progress_bar_ = 0;
-  chunk->high_water_mark_ = static_cast<int>(area_start - base);
+  chunk->high_water_mark_.SetValue(static_cast<intptr_t>(area_start - base));
   chunk->set_parallel_sweeping(SWEEPING_DONE);
   chunk->mutex_ = NULL;
   chunk->available_in_small_free_list_ = 0;