Add PTHREAD_PRIO_INHERIT Locks for Mac

base/synchronization/lock_impl.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_SYNCHRONIZATION_LOCK_IMPL_H_
 #define BASE_SYNCHRONIZATION_LOCK_IMPL_H_
 
 #include "base/base_export.h"
 #include "base/macros.h"
 #include "build/build_config.h"
@@ skipping 30 matching lines @@
 
   // Release the lock.  This must only be called by the lock's holder: after
   // a successful call to Try, or a call to Lock.
   void Unlock();
 
   // Return the native underlying lock.
   // TODO(awalker): refactor lock and condition variables so that this is
   // unnecessary.
   NativeHandle* native_handle() { return &native_handle_; }
 
+#if defined(OS_POSIX)

[danakj, 2016/07/27 22:47:53]

ditto

[robliao, 2016/07/28 20:06:09]

See previous comment.

+  // Whether this lock will attempt to use priority inheritance.
+  static bool PriorityInheritanceAvailable();
+#endif
+
  private:
   NativeHandle native_handle_;
 
   DISALLOW_COPY_AND_ASSIGN(LockImpl);
 };
 
 }  // namespace internal
 }  // namespace base
 
 #endif  // BASE_SYNCHRONIZATION_LOCK_IMPL_H_