[LayoutNG] Add NGInlineBreakToken and back of NGInlineLayoutAlgorithm

third_party/WebKit/Source/core/layout/ng/ng_line_breaker.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 NGLineBreaker_h
+#define NGLineBreaker_h
+
+#include "core/CoreExport.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class NGInlineLayoutAlgorithm;
+
+// Represents a line breaker.
+class CORE_EXPORT NGLineBreaker {
+  STACK_ALLOCATED();
+
+ public:
+  void BreakLines(NGInlineLayoutAlgorithm*, const String&, unsigned);
+};
+
+}  // namespace blink
+
+#endif  // NGLineBreaker_h