Revert of Test RTC_DCHECK_IS_ON instead of checking DCHECK_ALWAYS_ON everywhere

webrtc/base/sequenced_task_checker.h

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_BASE_SEQUENCED_TASK_CHECKER_H_
 #define WEBRTC_BASE_SEQUENCED_TASK_CHECKER_H_
 
 // Apart from debug builds, we also enable the sequence checker in
-// builds with RTC_DCHECK_IS_ON so that trybots and waterfall bots
+// builds with DCHECK_ALWAYS_ON so that trybots and waterfall bots
 // with this define will get the same level of checking as debug bots.
-#define ENABLE_SEQUENCED_TASK_CHECKER RTC_DCHECK_IS_ON
+//
+// Note that this does not perfectly match situations where RTC_DCHECK is
+// enabled.  For example a non-official release build may have
+// DCHECK_ALWAYS_ON undefined (and therefore SequencedTaskChecker would be
+// disabled) but have RTC_DCHECKs enabled at runtime.
+#if (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON))
+#define ENABLE_SEQUENCED_TASK_CHECKER 1
+#else
+#define ENABLE_SEQUENCED_TASK_CHECKER 0
+#endif
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/base/thread_annotations.h"
 #include "webrtc/base/sequenced_task_checker_impl.h"
 
 namespace rtc {
 
 // Do nothing implementation, for use in release mode.
 //
@@ skipping 41 matching lines @@
 
 }  // namespace internal
 
 #define RTC_DCHECK_CALLED_SEQUENTIALLY(x) \
   rtc::internal::SequencedTaskCheckerScope checker(x)
 
 #undef ENABLE_SEQUENCED_TASK_CHECKER
 
 }  // namespace rtc
 #endif  // WEBRTC_BASE_SEQUENCED_TASK_CHECKER_H_