Allow assertions to be enabled in Blink Release builds.

Source/core/dom/shadow/ComposedTreeWalker.h

 /*
  * Copyright (C) 2012 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.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 56 matching lines @@
 private:
     ComposedTreeWalker(const Node*, ParentTraversalDetails*);
 
     enum TraversalDirection {
         TraversalDirectionForward,
         TraversalDirectionBackward
     };
 
     void assertPrecondition() const
     {
-#ifndef NDEBUG
+#if ENABLE(ASSERT)
         ASSERT(m_node);
         ASSERT(!m_node->isShadowRoot());
         ASSERT(!isActiveInsertionPoint(*m_node));
 #endif
     }
 
     void assertPostcondition() const
     {
-#ifndef NDEBUG
+#if ENABLE(ASSERT)
         if (m_node)
             assertPrecondition();
 #endif
     }
 
     static Node* traverseNode(const Node*, TraversalDirection);
     static Node* traverseLightChildren(const Node*, TraversalDirection);
 
     Node* traverseFirstChild(const Node*) const;
     Node* traverseLastChild(const Node*) const;
@@ skipping 11 matching lines @@
     static Node* traverseBackToYoungerShadowRoot(const Node*, TraversalDirection);
 
     Node* traverseParentOrHost(const Node*) const;
 
     RawPtrWillBeMember<const Node> m_node;
 };
 
 inline ComposedTreeWalker::ComposedTreeWalker(const Node* node, StartPolicy startPolicy)
     : m_node(node)
 {
-#ifndef NDEBUG
+#if ENABLE(ASSERT)
     if (m_node && startPolicy == CannotStartFromShadowBoundary)
         assertPrecondition();
 #endif
 }
 
 inline void ComposedTreeWalker::parent()
 {
     assertPrecondition();
     m_node = traverseParent(m_node);
     assertPostcondition();
@@ skipping 77 matching lines @@
 
 inline Node* ComposedTreeWalker::traverseLastChild(const Node* node) const
 {
     ASSERT(node);
     return traverseChild(node, TraversalDirectionBackward);
 }
 
 } // namespace
 
 #endif