Update to Chromium //base at Chromium commit e3a753f17bac62738b0dbf0b36510f767b081e4b.

synchronization/condition_variable_posix.cc

Index: synchronization/condition_variable_posix.cc
diff --git a/synchronization/condition_variable_posix.cc b/synchronization/condition_variable_posix.cc
index 013284c888f72993b81a75f0b56a28bd653e6e3a..c9a2ec43f829e7fdbb73351e8739ad5e699150eb 100644
--- a/synchronization/condition_variable_posix.cc
+++ b/synchronization/condition_variable_posix.cc
@@ -42,6 +42,20 @@ ConditionVariable::ConditionVariable(Lock* user_lock)
 }
 
 ConditionVariable::~ConditionVariable() {
+#if defined(OS_MACOSX)
+  // This hack is necessary to avoid a fatal pthreads subsystem bug in the
+  // Darwin kernel. http://crbug.com/517681.
+  {
+    base::Lock lock;
+    base::AutoLock l(lock);
+    struct timespec ts;
+    ts.tv_sec = 0;
+    ts.tv_nsec = 1;
+    pthread_cond_timedwait_relative_np(&condition_, lock.lock_.native_handle(),
+                                       &ts);
+  }
+#endif
+
   int rv = pthread_cond_destroy(&condition_);
   DCHECK_EQ(0, rv);
 }