Clarify that Blink does not support a re-distribution across v0 and v1 shadow trees

third_party/WebKit/Source/core/dom/shadow/SlotAssignment.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/dom/shadow/SlotAssignment.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/shadow/ElementShadow.h"
@@ skipping 22 matching lines @@
     Name2Slot name2slot;
 
     const HeapVector<Member<HTMLSlotElement>>& slots = shadowRoot.descendantSlots();
 
     for (Member<HTMLSlotElement> slot : slots) {
         slot->willUpdateDistribution();
         name2slot.add(slot->name(), slot.get());
     }
 
     for (Node& child : NodeTraversal::childrenOf(*shadowRoot.host())) {
-        if (child.isElementNode() && isActiveInsertionPoint(child)) {
-            // TODO(hayato): Support re-distribution across v0 and v1 shadow trees
+        if (child.isInsertionPoint()) {

[hayato, 2016/04/11 09:34:40]

Strictly speaking, this is the behavior change. However, let me omit to write a
test for that because it is no worth having a test for that.

[kochi, 2016/04/11 10:35:33]

Acknowledged.

+            // A re-distribution across v0 and v1 shadow trees is not supported.
             detachNotAssignedNode(child);
             continue;
         }
         if (!child.slottable()) {
             detachNotAssignedNode(child);
             continue;
         }
         AtomicString slotName = child.slotName();
         HTMLSlotElement* slot = name2slot.get(slotName);
         if (slot)
@@ skipping 21 matching lines @@
     if (slot.isChildOfV1ShadowHost())
         slot.parentElementShadow()->setNeedsDistributionRecalc();
 }
 
 DEFINE_TRACE(SlotAssignment)
 {
     visitor->trace(m_assignment);
 }
 
 } // namespace blink