Remove all atomic access from store buffer.

src/heap/store-buffer.cc

 // Copyright 2011 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 <algorithm>
 
 #include "src/v8.h"
 
-#include "src/base/atomicops.h"
 #include "src/counters.h"
 #include "src/heap/store-buffer-inl.h"
 
 namespace v8 {
 namespace internal {
 
 StoreBuffer::StoreBuffer(Heap* heap)
     : heap_(heap),
       start_(NULL),
       limit_(NULL),
@@ skipping 336 matching lines @@
   }
 }
 
 
 void StoreBuffer::ClearInvalidStoreBufferEntries() {
   Compact();
   Address* new_top = old_start_;
   for (Address* current = old_start_; current < old_top_; current++) {
     Address addr = *current;
     Object** slot = reinterpret_cast<Object**>(*current);
-    // Use a NoBarrier_Load here since the slot can be in a dead object
-    // which may be touched by the concurrent sweeper thread.
-    Object* object = reinterpret_cast<Object*>(
-        base::NoBarrier_Load(reinterpret_cast<base::AtomicWord*>(slot)));
+    Object* object = *slot;
     if (heap_->InNewSpace(object)) {
       if (heap_->mark_compact_collector()->IsSlotInLiveObject(
               reinterpret_cast<HeapObject**>(slot),
               reinterpret_cast<HeapObject*>(object))) {
         *new_top++ = addr;
       }
     }
   }
   old_top_ = new_top;
   ClearFilteringHashSets();
@@ skipping 186 matching lines @@
     }
     old_buffer_is_sorted_ = false;
     old_buffer_is_filtered_ = false;
     *old_top_++ = reinterpret_cast<Address>(int_addr << kPointerSizeLog2);
     DCHECK(old_top_ <= old_limit_);
   }
   heap_->isolate()->counters()->store_buffer_compactions()->Increment();
 }
 }
 }  // namespace v8::internal