make debug mode ~20% faster on linux

base/synchronization/lock.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_H_
 #define BASE_SYNCHRONIZATION_LOCK_H_
 
 #include "base/base_export.h"
 #include "base/synchronization/lock_impl.h"
 #include "base/threading/platform_thread.h"
@@ skipping 62 matching lines @@
   // Members and routines taking care of locks assertions.
   // Note that this checks for recursive locks and allows them
   // if the variable is set.  This is allowed by the underlying implementation
   // on windows but not on Posix, so we're doing unneeded checks on Posix.
   // It's worth it to share the code.
   void CheckHeldAndUnmark();
   void CheckUnheldAndMark();
 
   // All private data is implicitly protected by lock_.
   // Be VERY careful to only access members under that lock.
-
-  // Determines validity of owning_thread_id_.  Needed as we don't have
-  // a null owning_thread_id_ value.
-  bool owned_by_thread_;
-  base::PlatformThreadId owning_thread_id_;
+  base::PlatformThreadRef owning_thread_ref_;
 #endif  // NDEBUG
 
   // Platform specific underlying lock implementation.
   internal::LockImpl lock_;
 
   DISALLOW_COPY_AND_ASSIGN(Lock);
 };
 
 // A helper class that acquires the given Lock while the AutoLock is in scope.
 class AutoLock {
@@ skipping 33 matching lines @@
   }
 
  private:
   Lock& lock_;
   DISALLOW_COPY_AND_ASSIGN(AutoUnlock);
 };
 
 }  // namespace base
 
 #endif  // BASE_SYNCHRONIZATION_LOCK_H_