Implement the inert attribute

third_party/WebKit/Source/core/dom/shadow/FlatTreeTraversal.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 107 matching lines @@
   static Node* LastWithin(const Node&);
   static Node& LastWithinOrSelf(const Node&);
 
  private:
   enum TraversalDirection {
     kTraversalDirectionForward,
     kTraversalDirectionBackward
   };
 
   static void AssertPrecondition(const Node& node) {
-    DCHECK(!node.NeedsDistributionRecalc());
+    if (node.NeedsDistributionRecalc()) {
+      LOG(INFO) << node << " needs recalc";

[esprehn, 2017/05/12 21:16:54]

This is called all over the place, you're making the release binary slower by
adding info level logging. This needs to be removed before landing.

[aboxhall, 2017/05/18 01:30:49]

Done.

+      DCHECK(!node.NeedsDistributionRecalc());

[esprehn, 2017/05/12 21:16:54]

Revert this change to just DCHECK.

[aboxhall, 2017/05/18 01:30:49]

Done.

+    }
     DCHECK(node.CanParticipateInFlatTree());
   }
 
   static void AssertPostcondition(const Node* node) {
 #if DCHECK_IS_ON()
     if (node)
       AssertPrecondition(*node);
 #endif
   }
 
@@ skipping 157 matching lines @@
   return TraverseChild(node, kTraversalDirectionForward);
 }
 
 inline Node* FlatTreeTraversal::TraverseLastChild(const Node& node) {
   return TraverseChild(node, kTraversalDirectionBackward);
 }
 
 }  // namespace blink
 
 #endif