Merge arguments branch to bleeding merge.

src/v8.h

Index: src/v8.h
diff --git a/src/v8.h b/src/v8.h
index e74a60c2f29d1f77bf9050d2bf67dbc0a2376a98..9d985213dee44cca88691c5c1aba92675eff01ea 100644
--- a/src/v8.h
+++ b/src/v8.h
@@ -1,4 +1,4 @@
-// Copyright 2011 the V8 project authors. All rights reserved.
+// Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -35,10 +35,13 @@
 #if defined(GOOGLE3)
 // Google3 special flag handling.
 #if defined(DEBUG) && defined(NDEBUG)
-// V8 only uses DEBUG and whenever it is set we are building a debug
-// version of V8. We do not use NDEBUG and simply undef it here for
-// consistency.
+// If both are defined in Google3, then we are building an optimized v8 with
+// assertions enabled.
 #undef NDEBUG
+#elif !defined(DEBUG) && !defined(NDEBUG)
+// If neither is defined in Google3, then we are building a debug v8. Mark it
+// as such.
+#define DEBUG
 #endif
 #endif  // defined(GOOGLE3)