Use DCHECK_IS_ON() instead of !NDEBUG for debug logic (issue #1961)

libcef_dll/base/cef_lock.cc

@@ -6,11 +6,11 @@
 // is functionally a wrapper around the LockImpl class, so the only
 // real intelligence in the class is in the debugging logic.
 
-#if !defined(NDEBUG)
-
 #include "include/base/cef_lock.h"
 #include "include/base/cef_logging.h"
 
+#if DCHECK_IS_ON()
+
 namespace base {
 namespace cef_internal {
 
@@ -43,4 +43,4 @@ void Lock::CheckUnheldAndMark() {
 }  // namespace cef_internal
 }  // namespace base
 
-#endif  // NDEBUG
+#endif  // DCHECK_IS_ON()