Replace tests of ASSERT_ENABLED with ENABLE(ASSERT).

Source/core/dom/DocumentLifecycle.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 114 matching lines @@
     void ensureStateAtMost(State);
 
     void incrementDetachCount() { m_detachCount++; }
     void decrementDetachCount()
     {
         ASSERT(m_detachCount > 0);
         m_detachCount--;
     }
 
 private:
-#if ASSERT_ENABLED
+#if ENABLE(ASSERT)
     bool canAdvanceTo(State) const;
     bool canRewindTo(State) const;
 #endif
 
     State m_state;
     int m_detachCount;
 };
 
 inline bool DocumentLifecycle::stateAllowsTreeMutations() const
 {
@@ skipping 16 matching lines @@
         || m_state == StyleClean
         || m_state == InPreLayout
         || m_state == LayoutClean
         || m_state == CompositingClean
         || m_state == Stopping;
 }
 
 }
 
 #endif