Tidy up memory barriers.

Change-Id: I937ea93e6df1835ecfe2d4bb7d84c24fe7fc097b
diff --git a/runtime/monitor.cc b/runtime/monitor.cc
index ef9a9ce..4186693 100644
--- a/runtime/monitor.cc
+++ b/runtime/monitor.cc
@@ -98,12 +98,12 @@
 
 int32_t Monitor::GetHashCode() {
   while (!HasHashCode()) {
-    if (hash_code_.compare_and_swap(0, mirror::Object::GenerateIdentityHashCode())) {
+    if (hash_code_.CompareAndSwap(0, mirror::Object::GenerateIdentityHashCode())) {
       break;
     }
   }
   DCHECK(HasHashCode());
-  return hash_code_.load();
+  return hash_code_.Load();
 }
 
 bool Monitor::Install(Thread* self) {
@@ -660,6 +660,7 @@
       case LockWord::kUnlocked: {
         LockWord thin_locked(LockWord::FromThinLockId(thread_id, 0));
         if (sirt_obj->CasLockWord(lock_word, thin_locked)) {
+          QuasiAtomic::MembarLoadLoad();
           return;  // Success!
         }
         continue;  // Go again.