Enable ThreadChecker in non-debug builds if DCHECK_ALWAYS_ON is

base/threading/thread_checker_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_THREADING_THREAD_CHECKER_IMPL_H_
 #define BASE_THREADING_THREAD_CHECKER_IMPL_H_
 #pragma once
 
 #include "base/base_export.h"
 #include "base/synchronization/lock.h"
@@ skipping 12 matching lines @@
   ThreadCheckerImpl();
   ~ThreadCheckerImpl();
 
   bool CalledOnValidThread() const;
 
   // Changes the thread that is checked for in CalledOnValidThread.  This may
   // be useful when an object may be created on one thread and then used
   // exclusively on another thread.
   void DetachFromThread();
 
+  // Returns true if thread checking is enabled.
+  static bool IsEnabled();
+
  private:
   void EnsureThreadIdAssigned() const;
 
   mutable base::Lock lock_;
   // This is mutable so that CalledOnValidThread can set it.
   // It's guarded by |lock_|.
   mutable PlatformThreadId valid_thread_id_;
 };
 
 }  // namespace base
 
 #endif  // BASE_THREADING_THREAD_CHECKER_IMPL_H_