Merge tcmalloc r111 (perftools v. 1.8) with the chromium/ branch.

third_party/tcmalloc/chromium/src/base/spinlock_internal.cc

 /* Copyright (c) 2010, 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 26 matching lines @@
 // spin loop on location *w, whose previously observed value was "value".
 // SpinLockDelay() may do nothing, may yield the CPU, may sleep a clock tick,
 // or may wait for a delay that can be truncated by a call to SpinlockWake(w).
 // In all cases, it must return in bounded time even if SpinlockWake() is not
 // called.
 
 #include "base/spinlock_internal.h"
 
 #if defined(_WIN32)
 #include "base/spinlock_win32-inl.h"
-#elif defined(__linux__)
+#elif defined(__linux__) && !defined(__native_client__)

[jar (doing other things), 2011/07/31 08:19:39]

I was expecting items provided by more mainstream TCMalloc.  This looks like a
Chromium specific change.  

Was this added because we couldn't compile new stuff without this change?

 #include "base/spinlock_linux-inl.h"
 #else
 #include "base/spinlock_posix-inl.h"
 #endif
 
 namespace base {
 namespace internal {
 
 // See spinlock_internal.h for spec.
 int32 SpinLockWait(volatile Atomic32 *w, int n,
@@ skipping 10 matching lines @@
     } else if (trans[i].to == v ||   // null transition
                base::subtle::Acquire_CompareAndSwap(w, v, trans[i].to) == v) {
       done = trans[i].done;
     }
   }
   return v;
 }
 
 } // namespace internal
 } // namespace base