[LayoutNG] Add NGLineBoxFragment

third_party/WebKit/Source/core/layout/ng/ng_physical_line_box_fragment.h

+// Copyright 2017 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 NGPhysicalLineBoxFragment_h
+#define NGPhysicalLineBoxFragment_h
+
+#include "core/CoreExport.h"
+#include "core/layout/ng/geometry/ng_logical_offset.h"
+#include "core/layout/ng/ng_line_height_metrics.h"
+#include "core/layout/ng/ng_physical_fragment.h"
+
+namespace blink {
+
+class CORE_EXPORT NGPhysicalLineBoxFragment final : public NGPhysicalFragment {
+ public:
+  // This modifies the passed-in children vector.
+  NGPhysicalLineBoxFragment(NGPhysicalSize size,
+                            Vector<RefPtr<NGPhysicalFragment>>& children,
+                            const NGLineHeightMetrics&,
+                            RefPtr<NGBreakToken> break_token = nullptr);
+
+  const Vector<RefPtr<NGPhysicalFragment>>& Children() const {
+    return children_;
+  }
+
+  const NGLineHeightMetrics& Metrics() const { return metrics_; }
+
+ private:
+  Vector<RefPtr<NGPhysicalFragment>> children_;
+
+  NGLineHeightMetrics metrics_;
+};
+
+DEFINE_TYPE_CASTS(NGPhysicalLineBoxFragment,
+                  NGPhysicalFragment,
+                  fragment,
+                  fragment->Type() == NGPhysicalFragment::kFragmentLineBox,
+                  fragment.Type() == NGPhysicalFragment::kFragmentLineBox);
+
+}  // namespace blink
+
+#endif  // NGPhysicalBoxFragment_h