Revert "Remove obsolete float-management code from line layout"

Source/core/layout/line/TrailingFloatsRootInlineBox.h

 /*
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef TypesettingFeatures_h
-#define TypesettingFeatures_h
+#ifndef TrailingFloatsRootInlineBox_h
+#define TrailingFloatsRootInlineBox_h
+
+#include "core/layout/line/RootInlineBox.h"
 
 namespace blink {
 
-enum TypesettingFeature {
-    Kerning = 1 << 0,
-    Ligatures = 1 << 1,
+class TrailingFloatsRootInlineBox final : public RootInlineBox {
+public:
+    TrailingFloatsRootInlineBox(LayoutBlockFlow& block)
+        : RootInlineBox(block)
+    {
+        setHasVirtualLogicalHeight();
+    }
+
+private:
+    virtual LayoutUnit virtualLogicalHeight() const override { return 0; }
 };
 
-typedef unsigned TypesettingFeatures;
-
 } // namespace blink
 
-#endif // TypesettingFeatures_h
+#endif // TrailingFloatsRootInlineBox_h