Some base/ progress towards building on Linux x86-64.

base/atomicops_internals_x86_gcc.h

Index: base/atomicops_internals_x86_gcc.h
diff --git a/base/atomicops_internals_x86_gcc.h b/base/atomicops_internals_x86_gcc.h
index f523f6f725fd12695b7b0eeddd346d8d251e8021..002734b2b8dfe319a0f9ef63aa2c6e25132e4f73 100644
--- a/base/atomicops_internals_x86_gcc.h
+++ b/base/atomicops_internals_x86_gcc.h
@@ -238,6 +238,23 @@ inline Atomic64 Release_Load(volatile const Atomic64* ptr) {
   MemoryBarrier();
   return *ptr;
 }
+
+inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
+                                       Atomic64 old_value,
+                                       Atomic64 new_value) {
+  Atomic64 x = NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+  if (AtomicOps_Internalx86CPUFeatures.has_amd_lock_mb_bug) {
+    __asm__ __volatile__("lfence" : : : "memory");
+  }
+  return x;
+}
+
+inline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
+                                       Atomic64 old_value,
+                                       Atomic64 new_value) {
+  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+}
+
 #endif  // defined(__x86_64__)
 
 } // namespace base::subtle