[WIP] do something :-)

Source/core/dom/shadow/ShadowRoot.cpp

 /*
  * Copyright (C) 2011 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 22 matching lines @@
 #include "core/css/resolver/StyleResolverParentScope.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/StyleEngine.h"
 #include "core/dom/Text.h"
 #include "core/dom/shadow/ElementShadow.h"
 #include "core/dom/shadow/InsertionPoint.h"
 #include "core/dom/shadow/ShadowRootRareData.h"
 #include "core/editing/serializers/Serialization.h"
 #include "core/html/HTMLShadowElement.h"
 #include "public/platform/Platform.h"
+#include "wtf/SizeAssertions.h"
 
 namespace blink {
 
-struct SameSizeAsShadowRoot : public DocumentFragment, public TreeScope, public DoublyLinkedListNode<ShadowRoot> {
-#if ENABLE(OILPAN)
-    char emptyClassFieldsDueToGCMixinMarker[1];
-#endif
-    void* pointers[3];
-    unsigned countersAndFlags[1];
-};
-
-static_assert(sizeof(ShadowRoot) == sizeof(SameSizeAsShadowRoot), "ShadowRoot should stay small");
+ASSERT_SIZE(ShadowRoot, 104, 200);
 
 ShadowRoot::ShadowRoot(Document& document, ShadowRootType type)
     : DocumentFragment(0, CreateShadowRoot)
     , TreeScope(*this, document)
     , m_prev(nullptr)
     , m_next(nullptr)
     , m_numberOfStyles(0)
     , m_type(static_cast<unsigned>(type))
     , m_registeredWithParentShadowRoot(false)
     , m_descendantInsertionPointsIsValid(false)
@@ skipping 261 matching lines @@
 DEFINE_TRACE(ShadowRoot)
 {
     visitor->trace(m_prev);
     visitor->trace(m_next);
     visitor->trace(m_shadowRootRareData);
     TreeScope::trace(visitor);
     DocumentFragment::trace(visitor);
 }
 
 }