Implement the inert attribute

third_party/WebKit/Source/core/dom/shadow/FlatTreeTraversal.h

Index: third_party/WebKit/Source/core/dom/shadow/FlatTreeTraversal.h
diff --git a/third_party/WebKit/Source/core/dom/shadow/FlatTreeTraversal.h b/third_party/WebKit/Source/core/dom/shadow/FlatTreeTraversal.h
index f8288ed19cd728045abe8ae48aa585a28232fe07..15bb820a30f60cdbee85b1444b8799a0a8448506 100644
--- a/third_party/WebKit/Source/core/dom/shadow/FlatTreeTraversal.h
+++ b/third_party/WebKit/Source/core/dom/shadow/FlatTreeTraversal.h
@@ -125,7 +125,10 @@ class CORE_EXPORT FlatTreeTraversal {
   };
 
   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());
   }