Reschedule sibling invalidations as descendant on removal.

third_party/WebKit/Source/core/css/invalidation/StyleInvalidator.cpp

 // Copyright 2014 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/css/invalidation/StyleInvalidator.h"
 
 #include "core/css/invalidation/InvalidationSet.h"
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/ElementTraversal.h"
@@ skipping 114 matching lines @@
             SubtreeStyleChange, StyleChangeReasonForTracing::create(
                                     StyleChangeReason::StyleInvalidator));
         return;
       }
       if (!pendingInvalidations.descendants().contains(descendants))
         pendingInvalidations.descendants().push_back(descendants);
     }
   }
 }
 
+void StyleInvalidator::rescheduleSiblingInvalidationsAsDescendants(
+    Element& element) {
+  PendingInvalidations* pendingInvalidations =
+      m_pendingInvalidationMap.get(&element);
+  if (!pendingInvalidations || pendingInvalidations->siblings().isEmpty())
+    return;
+
+  InvalidationLists invalidationLists;
+  for (const auto& invalidationSet : pendingInvalidations->siblings()) {
+    invalidationLists.descendants.push_back(invalidationSet);
+    if (DescendantInvalidationSet* descendants =
+            toSiblingInvalidationSet(*invalidationSet).siblingDescendants()) {
+      invalidationLists.descendants.push_back(descendants);
+    }
+  }
+  DCHECK(element.parentNode());

[esprehn, 2016/12/22 17:19:59]

I personally like to put these at the top of the function to make the call
invariants clear.

[rune, 2016/12/23 00:15:20]

Done.

+  scheduleInvalidationSetsForNode(invalidationLists, *element.parentNode());
+}
+
 void StyleInvalidator::clearInvalidation(ContainerNode& node) {
   if (!node.needsStyleInvalidation())
     return;
   m_pendingInvalidationMap.remove(&node);
   node.clearNeedsStyleInvalidation();
 }
 
 PendingInvalidations& StyleInvalidator::ensurePendingInvalidations(
     ContainerNode& node) {
   PendingInvalidationMap::AddResult addResult =
@@ skipping 264 matching lines @@
       continue;
     if (recursionData.matchesCurrentInvalidationSetsAsSlotted(
             toElement(*distributedNode)))
       distributedNode->setNeedsStyleRecalc(
           LocalStyleChange, StyleChangeReasonForTracing::create(
                                 StyleChangeReason::StyleInvalidator));
   }
 }
 
 }  // namespace blink