Use NoBarrier getters and setters for FixedArray.

src/heap/spaces.h

Index: src/heap/spaces.h
diff --git a/src/heap/spaces.h b/src/heap/spaces.h
index fd477fa1cb88df15642e596ff6a313fab5146318..dc63e85a2aab4d0e88cfc176d38c2fc4fc76650d 100644
--- a/src/heap/spaces.h
+++ b/src/heap/spaces.h
@@ -552,10 +552,11 @@ class MemoryChunk {
   void set_prev_chunk(MemoryChunk* prev) { prev_chunk_.SetValue(prev); }
 
   Space* owner() const {
-    if ((reinterpret_cast<intptr_t>(owner_) & kPageHeaderTagMask) ==
-        kPageHeaderTag) {
-      return reinterpret_cast<Space*>(reinterpret_cast<intptr_t>(owner_) -
-                                      kPageHeaderTag);
+    intptr_t owner_value = base::NoBarrierAtomicValue<intptr_t>::FromAddress(
+                               const_cast<Address*>(&owner_))
+                               ->Value();
+    if ((owner_value & kPageHeaderTagMask) == kPageHeaderTag) {
+      return reinterpret_cast<Space*>(owner_value - kPageHeaderTag);
     } else {
       return nullptr;
     }