Enable ThreadChecker in non-debug builds if DCHECK_ALWAYS_ON is

base/threading/thread_checker_impl.cc

 // 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.
 
 #include "base/threading/thread_checker_impl.h"
 
 namespace base {
 
 ThreadCheckerImpl::ThreadCheckerImpl()
     : valid_thread_id_(kInvalidThreadId) {
@@ skipping 13 matching lines @@
   valid_thread_id_ = kInvalidThreadId;
 }
 
 void ThreadCheckerImpl::EnsureThreadIdAssigned() const {
   AutoLock auto_lock(lock_);
   if (valid_thread_id_ != kInvalidThreadId)
     return;
   valid_thread_id_ = PlatformThread::CurrentId();
 }
 
+// static
+bool ThreadCheckerImpl::IsEnabled() {
+  return true;
+}
+
 }  // namespace base