Use C++11 atomics

base/atomicops.h

Index: base/atomicops.h
diff --git a/base/atomicops.h b/base/atomicops.h
index 84be8c04bc00e57ebbd701c803d2b3c24a314723..294e5985ff6c123c111646e820a0adc18ad5a0ca 100644
--- a/base/atomicops.h
+++ b/base/atomicops.h
@@ -138,23 +138,8 @@ Atomic64 Release_Load(volatile const Atomic64* ptr);
 }  // namespace base
 
 // Include our platform specific implementation.
-#if defined(THREAD_SANITIZER)
-#include "base/atomicops_internals_tsan.h"
-#elif defined(OS_WIN) && defined(COMPILER_MSVC) && defined(ARCH_CPU_X86_FAMILY)
-#include "base/atomicops_internals_x86_msvc.h"
-#elif defined(OS_MACOSX)
-#include "base/atomicops_internals_mac.h"
-#elif defined(OS_NACL)
-#include "base/atomicops_internals_gcc.h"
-#elif defined(COMPILER_GCC) && defined(ARCH_CPU_ARMEL)
-#include "base/atomicops_internals_arm_gcc.h"
-#elif defined(COMPILER_GCC) && defined(ARCH_CPU_ARM64)
-#include "base/atomicops_internals_arm64_gcc.h"
-#elif defined(COMPILER_GCC) && defined(ARCH_CPU_X86_FAMILY)
-#include "base/atomicops_internals_x86_gcc.h"
-#elif defined(COMPILER_GCC) && \
-      (defined(ARCH_CPU_MIPS_FAMILY) || defined(ARCH_CPU_MIPS64_FAMILY))
-#include "base/atomicops_internals_mips_gcc.h"
+#if defined(__cplusplus) && (__cplusplus >= 201103L) // C++11
+#include "base/atomicops_internals_portable.h"
 #else
 #error "Atomic operations are not supported on your platform"
 #endif