Create LineLayout api

Source/core/layout/api/LineLayoutBox.cpp

Index: Source/core/layout/api/LineLayoutBox.cpp
diff --git a/Source/core/layout/api/LineLayoutBox.cpp b/Source/core/layout/api/LineLayoutBox.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..12ab71f2f35b53fae3e324b56626548727841ae5
--- /dev/null
+++ b/Source/core/layout/api/LineLayoutBox.cpp
@@ -0,0 +1,43 @@
+// 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.
+
+#include "config.h"
+#include "core/layout/api/LineLayoutBox.h"
+
+#include "core/layout/LayoutBox.h"
+
+namespace blink {
+
+LineLayoutBox::LineLayoutBox(LayoutBox* layoutBox)
+    : LineLayoutItem(layoutBox)
+{
+}
+
+LineLayoutBox::LineLayoutBox(const LineLayoutItem& item)
+    : LineLayoutItem(item)
+{
+    ASSERT(!item.layoutObject() || item.layoutObject()->isBox());
+}
+
+void LineLayoutBox::setLogicalHeight(LayoutUnit size)
+{
+    toBox()->setLogicalHeight(size);
+}
+
+LayoutUnit LineLayoutBox::logicalHeight() const
+{
+    return toBox()->logicalHeight();
+}
+
+LayoutBox* LineLayoutBox::toBox()
+{
+    return toLayoutBox(layoutObject());
+}
+
+const LayoutBox* LineLayoutBox::toBox() const
+{
+    return toLayoutBox(layoutObject());
+}
+
+} // namespace blink