Remove begin/end subseq. display items, and store on PaintController instead.

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 "platform/wtf/Assertions.h"
-
-namespace blink {
-
-class BeginSubsequenceDisplayItem final : public PairedBeginDisplayItem {
- public:
-  BeginSubsequenceDisplayItem(const DisplayItemClient& client)
-      : PairedBeginDisplayItem(client, kSubsequence, sizeof(*this)) {}
-};
-
-class EndSubsequenceDisplayItem final : public PairedEndDisplayItem {
- public:
-  EndSubsequenceDisplayItem(const DisplayItemClient& client)
-      : PairedEndDisplayItem(client, kEndSubsequence, sizeof(*this)) {}
-
-#if DCHECK_IS_ON()
-  bool isEndAndPairedWith(DisplayItem::Type otherType) const final {
-    return getType() == kEndSubsequence && otherType == kSubsequence;
-  }
-#endif
-};
-
-}  // namespace blink
-
-#endif  // SubsequenceDisplayItem_h