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..fe3ec95f18913f489fd075cd99db7eeab2e35334
--- /dev/null
+++ b/Source/core/layout/api/LineLayoutBox.cpp
@@ -0,0 +1,23 @@
+// 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)

[esprehn, 2015/06/17 20:29:52]

All the constructors and destructors need to be inline, otherwise there's
function calls hiding in all the wrapping and unwrapping logic.

+{
+}
+
+LineLayoutBox::LineLayoutBox(const LineLayoutItem& item)
+    : LineLayoutItem(item)
+{
+    ASSERT(!item.layoutObject() || item.layoutObject()->isBox());
+}
+
+} // namespace blink