Unify usage of logging/assert macros in base/

base/logging.h

Index: base/logging.h
diff --git a/base/logging.h b/base/logging.h
index fd148aa2694700e910e79810635e60fb466e2b56..0edcf4df76968a7f96d96a208267542e450aa1f5 100644
--- a/base/logging.h
+++ b/base/logging.h
@@ -642,18 +642,13 @@ DEFINE_CHECK_OP_IMPL(GT, > )
 
 #endif  // ENABLE_DLOG
 
-// DEBUG_MODE is for uses like
+// DEBUG_MODE is for runtime uses like
 //   if (DEBUG_MODE) foo.CheckThatFoo();
-// instead of
-//   #ifndef NDEBUG
-//     foo.CheckThatFoo();
-//   #endif
-//
 // We tie its state to ENABLE_DLOG.
+//
+// For compile-time checks, #if ENABLE_DLOG can be used.
 enum { DEBUG_MODE = ENABLE_DLOG };
 
-#undef ENABLE_DLOG

[danakj, 2016/07/19 20:17:01]

Hm.. idk why we need both here. Can we just delete ENABLE_DLOG and use
DCHECK_IS_ON()?

[gab, 2016/07/20 02:43:58]

Sure, though it's a bit weird to have

#if DCHECK_IS_ON()
  bool result =
#endif
     MyCallWithResult();
  DLOG_IF(!result, "blah");

because DLOG and DCHECK are two different things. So I understand wanting two
macros even if they have the same definition... That's why I wanted to add
DLOG_IS_ON() but it already exists and means something else... Maybe we could
add DLOG_IS_ENABLED()?

Anyways, replaced ENABLE_DLOG with DCHECK_IS_ON() directly for now, let me know
what you think.

-
 #define DLOG(severity)                                          \
   LAZY_STREAM(LOG_STREAM(severity), DLOG_IS_ON(severity))