Also ignore NDEBUG for chromium code

src/v8.h

 // Copyright 2011 the V8 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.
 
 //
 // Top include for all V8 .cc files.
 //
 
 #ifndef V8_V8_H_
 #define V8_V8_H_
 
-#if defined(GOOGLE3)
-// Google3 special flag handling.
+#if defined(GOOGLE3) || defined(DCHECK_ALWAYS_ON)
+// Google3 and Chromium 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.
 #undef NDEBUG
 #endif
 #endif  // defined(GOOGLE3)
 
 // V8 only uses DEBUG, but included external files
 // may use NDEBUG - make sure they are consistent.
@@ skipping 72 matching lines @@
 };
 
 
 // JavaScript defines two kinds of 'nil'.
 enum NilValue { kNullValue, kUndefinedValue };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_V8_H_