Add support for enabling DCHECKs in release mode

src/transitions.h

 // Copyright 2012 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.
 
 #ifndef V8_TRANSITIONS_H_
 #define V8_TRANSITIONS_H_
 
 #include "src/checks.h"
 #include "src/elements-kind.h"
 #include "src/heap/heap.h"
@@ skipping 145 matching lines @@
   static const int kTransitionSize = 2;
 
 #ifdef OBJECT_PRINT
   // For our gdb macros, we should perhaps change these in the future.
   void Print();
 
   // Print all the transitions.
   void PrintTransitions(std::ostream& os, bool print_header = true);  // NOLINT
 #endif
 
-#ifdef DEBUG
+#if DCHECK_IS_ON
   bool IsSortedNoDuplicates(int valid_entries = -1);
   bool IsConsistentWithBackPointers(Map* current_map);
   bool IsEqualTo(TransitionArray* other);
 #endif
 
   // The maximum number of transitions we want in a transition array (should
   // fit in a page).
   static const int kMaxNumberOfTransitions = 1024 + 512;
 
   // Returns the fixed array length required to hold number_of_transitions
@@ skipping 34 matching lines @@
                                                 int origin_transition,
                                                 int target_transition);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(TransitionArray);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TRANSITIONS_H_