Update the tcmalloc vendor branch to r144 (gperftools 2.0).

third_party/tcmalloc/vendor/src/base/spinlock_linux-inl.h

Index: third_party/tcmalloc/vendor/src/base/spinlock_linux-inl.h
diff --git a/third_party/tcmalloc/vendor/src/base/spinlock_linux-inl.h b/third_party/tcmalloc/vendor/src/base/spinlock_linux-inl.h
index a178dd5a813ea9fc3db1f0d5ee4168a18c613c3a..bee2d4cedb123ecd61889fc18775a8e60d804e5c 100644
--- a/third_party/tcmalloc/vendor/src/base/spinlock_linux-inl.h
+++ b/third_party/tcmalloc/vendor/src/base/spinlock_linux-inl.h
@@ -31,6 +31,7 @@
  * This file is a Linux-specific part of spinlock_internal.cc
  */
 
+#include <errno.h>
 #include <sched.h>
 #include <time.h>
 #include <limits.h>
@@ -75,12 +76,12 @@ void SpinLockDelay(volatile Atomic32 *w, int32 value, int loop) {
     struct timespec tm;
     tm.tv_sec = 0;
     if (have_futex) {
-      tm.tv_nsec = 1000000;   // 1ms; really we're trying to sleep for one
-                              // kernel clock tick
+      tm.tv_nsec = base::internal::SuggestedDelayNS(loop);
     } else {
       tm.tv_nsec = 2000001;   // above 2ms so linux 2.4 doesn't spin
     }
     if (have_futex) {
+      tm.tv_nsec *= 16;  // increase the delay; we expect explicit wakeups
       sys_futex(reinterpret_cast<int *>(const_cast<Atomic32 *>(w)),
                 FUTEX_WAIT | futex_private_flag,
                 value, reinterpret_cast<struct kernel_timespec *>(&tm));