[LayoutNG] Add NGLineBoxFragment

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

Index: third_party/WebKit/Source/core/layout/ng/ng_physical_linebox_fragment.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_physical_linebox_fragment.h b/third_party/WebKit/Source/core/layout/ng/ng_physical_linebox_fragment.h
new file mode 100644
index 0000000000000000000000000000000000000000..803622a829f60dadbf07d48f4d60e9183e3b2b0f
--- /dev/null
+++ b/third_party/WebKit/Source/core/layout/ng/ng_physical_linebox_fragment.h
@@ -0,0 +1,43 @@
+// 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