Experiment for updating the tcmalloc chromium branch to r144 (gperftools 2.0).

third_party/tcmalloc/chromium/src/base/spinlock_win32-inl.h

 /* Copyright (c) 2009, Google Inc.
  * All rights reserved.
  * 
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  * 
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 24 matching lines @@
 #include <windows.h>
 
 namespace base {
 namespace internal {
 
 void SpinLockDelay(volatile Atomic32 *w, int32 value, int loop) {
   if (loop == 0) {
   } else if (loop == 1) {
     Sleep(0);
   } else {
+    // TODO(dmikurube): Re-enable the commented-out code.
+    // We commented out the following line and used the old code "Sleep(1)"
+    // since base/atomicops-internals-windows.h doesn't support 64-bit
+    // operations.
+    //
+    // Commended-out code:
+    //   Sleep(base::internal::SuggestedDelayNS(loop) / 1000000);
     Sleep(1);
   }
 }
 
 void SpinLockWake(volatile Atomic32 *w, bool all) {
 }
 
 } // namespace internal
 } // namespace base