Add acquire/release to global variable.

base/metrics/persistent_histogram_allocator.cc

Index: base/metrics/persistent_histogram_allocator.cc
diff --git a/base/metrics/persistent_histogram_allocator.cc b/base/metrics/persistent_histogram_allocator.cc
index 011d8837adfaef2dc10926be1ca96e840bd3e36b..8cbced26ffe9c2b6487e1ff1f2d91b24ef217e02 100644
--- a/base/metrics/persistent_histogram_allocator.cc
+++ b/base/metrics/persistent_histogram_allocator.cc
@@ -825,8 +825,8 @@ void GlobalHistogramAllocator::Set(
   // likely has histograms stored within it. If the backing memory is also
   // also released, future accesses to those histograms will seg-fault.
   CHECK(!subtle::NoBarrier_Load(&g_allocator));
-  subtle::NoBarrier_Store(&g_allocator,
-                          reinterpret_cast<uintptr_t>(allocator.release()));
+  subtle::Release_Store(&g_allocator,
+                        reinterpret_cast<uintptr_t>(allocator.release()));
   size_t existing = StatisticsRecorder::GetHistogramCount();
 
   DVLOG_IF(1, existing)
@@ -836,7 +836,7 @@ void GlobalHistogramAllocator::Set(
 // static
 GlobalHistogramAllocator* GlobalHistogramAllocator::Get() {
   return reinterpret_cast<GlobalHistogramAllocator*>(
-      subtle::NoBarrier_Load(&g_allocator));
+      subtle::Acquire_Load(&g_allocator));
 }
 
 // static
@@ -866,7 +866,7 @@ GlobalHistogramAllocator::ReleaseForTesting() {
     DCHECK_NE(kResultHistogram, data->name);
   }
 
-  subtle::NoBarrier_Store(&g_allocator, 0);
+  subtle::Release_Store(&g_allocator, 0);
   return WrapUnique(histogram_allocator);
 };