Adds TCMalloc support for Android.

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 29 matching lines @@
 // In all cases, it must return in bounded time even if SpinlockWake() is not
 // called.
 
 #include "base/spinlock_internal.h"
 
 // forward declaration for use by spinlock_*-inl.h
 namespace base { namespace internal { static int SuggestedDelayNS(int loop); }}
 
 #if defined(_WIN32)
 #include "base/spinlock_win32-inl.h"
-#elif defined(__linux__)
+#elif defined(__linux__) && !defined(__ANDROID__)

[Dai Mikurube (NOT FULLTIME), 2013/05/03 08:53:00]

spinlock_linux-inl doesn't work?  How about adding a TODO since we may finally
want to use linux version.

[bulach, 2013/05/07 14:55:51]

good point! I mistakenly "un"defined HAVE_SYS_SYSCALL, and broke this. since
android does have sys/syscall, removed this here.

 #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 32 matching lines @@
   // Select top 20..24 bits of lower 48 bits,
   // giving approximately 0ms to 16ms.
   // Mean is exponential in loop for first 32 iterations, then 8ms.
   // The futex path multiplies this by 16, since we expect explicit wakeups
   // almost always on that path.
   return r >> (44 - (loop >> 3));
 }
 
 } // namespace internal
 } // namespace base