Address Florian's comments.

runtime/vm/object.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 2778 matching lines @@
   RawArray* ic_data() const {
     return raw_ptr()->ic_data_;
   }
 
   void set_function(const Function& value) const;
   void set_target_name(const String& value) const;
   void set_deopt_id(intptr_t value) const;
   void set_num_args_tested(intptr_t value) const;
   void set_ic_data(const Array& value) const;
 
+#if defined(DEBUG)
   // Used in asserts to verify that a check is not added twice.
   bool HasCheck(const GrowableArray<intptr_t>& cids) const;
+#endif  // DEBUG
 
   intptr_t TestEntryLength() const;
   void WriteSentinel() const;
 
   HEAP_OBJECT_IMPLEMENTATION(ICData, Object);
   friend class Class;
 };
 
 
 class SubtypeTestCache : public Object {
@@ skipping 2924 matching lines @@
     if (this->CharAt(i) != str.CharAt(begin_index + i)) {
       return false;
     }
   }
   return true;
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_