Separate display item clients for negative and normal/positive z-order children

third_party/WebKit/Source/platform/graphics/paint/SubsequenceDisplayItem.h

 // 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.
 
 #ifndef SubsequenceDisplayItem_h
 #define SubsequenceDisplayItem_h
 
 #include "platform/geometry/FloatRect.h"
 #include "platform/graphics/paint/DisplayItem.h"
 #include "wtf/Assertions.h"
 
 namespace blink {
 
 class BeginSubsequenceDisplayItem final : public PairedBeginDisplayItem {
 public:
-    BeginSubsequenceDisplayItem(const DisplayItemClientWrapper& client, DisplayItem::Type type)
-        : PairedBeginDisplayItem(client, type, sizeof(*this))
-    {
-        ASSERT(DisplayItem::isSubsequenceType(type));
-    }
+    BeginSubsequenceDisplayItem(const DisplayItemClientWrapper& client)
+        : PairedBeginDisplayItem(client, Subsequence, sizeof(*this))
+    { }
 };
 
 class EndSubsequenceDisplayItem final : public PairedEndDisplayItem {
 public:
-    EndSubsequenceDisplayItem(const DisplayItemClientWrapper& client, DisplayItem::Type type)
-        : PairedEndDisplayItem(client, type, sizeof(*this))
-    {
-        ASSERT(DisplayItem::isEndSubsequenceType(type));
-    }
+    EndSubsequenceDisplayItem(const DisplayItemClientWrapper& client)
+        : PairedEndDisplayItem(client, EndSubsequence, sizeof(*this))
+    { }
 
 #if ENABLE(ASSERT)
     bool isEndAndPairedWith(DisplayItem::Type otherType) const final
     {
-        return otherType == DisplayItem::endSubsequenceTypeToSubsequenceType(type());
+        return type() == EndSubsequence && otherType == Subsequence;
     }
 #endif
 };
 
 } // namespace blink
 
 #endif // SubsequenceDisplayItem_h