Fix a bug in Arm64 atomicops.

base/atomicops_internals_arm64_gcc.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file is an internal atomic implementation, use base/atomicops.h instead.
 
 // TODO(rmcilroy): Investigate whether we can use __sync__ intrinsics instead of
 //                 the hand coded assembly without introducing perf regressions.
 // TODO(rmcilroy): Investigate whether we can use acquire / release versions of
 //                 exclusive load / store assembly instructions and do away with
@@ skipping 266 matching lines @@
     : [value]"r" (value)
     : "memory"
   );  // NOLINT
 }
 
 inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
   return *ptr;
 }
 
 inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
-  Atomic32 value;
+  Atomic64 value;
 
   __asm__ __volatile__ (  // NOLINT
     "ldar %x[value], %[ptr]  \n\t"
     : [value]"=r" (value)
     : [ptr]"Q" (*ptr)
     : "memory"
   );  // NOLINT
 
   return value;
 }
 
 inline Atomic64 Release_Load(volatile const Atomic64* ptr) {
   MemoryBarrier();
   return *ptr;
 }
 
 }  // namespace base::subtle
 }  // namespace base
 
 #endif  // BASE_ATOMICOPS_INTERNALS_ARM64_GCC_H_