Create LineLayout api

Source/core/layout/api/LineLayoutItem.h

Index: Source/core/layout/api/LineLayoutItem.h
diff --git a/Source/core/layout/api/LineLayoutItem.h b/Source/core/layout/api/LineLayoutItem.h
new file mode 100644
index 0000000000000000000000000000000000000000..64f45ed7d5b671d433d7560e503f0ba301fe3ff1
--- /dev/null
+++ b/Source/core/layout/api/LineLayoutItem.h
@@ -0,0 +1,80 @@
+// 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.
+
+#ifndef LineLayoutItem_h
+#define LineLayoutItem_h
+
+#include "platform/LayoutUnit.h"
+
+namespace blink {
+
+class ComputedStyle;
+class Document;
+class LayoutObject;
+
+class LineLayoutItem {
+public:
+    LineLayoutItem(LayoutObject*);
+    LineLayoutItem(const LineLayoutItem& item) : m_layoutObject(item.m_layoutObject) { }
+    LineLayoutItem() : m_layoutObject(0) { }
+
+    // TODO: add operator= ?
+
+    // TODO(leviw): re-enable when we don't have the LayoutObject*() operator.
+    // This conversion operator allows implicit conversion to bool but not to
+    // other integer types.
+    // typedef void* UnspecifiedBoolType;
+    // operator UnspecifiedBoolType() const { return m_layoutObject; }
+
+    // TODO(leviw): Remove this. It's only here to make things compile before
+    // switching all of core/layout/line to using the API.
+    operator LayoutObject*() const { return m_layoutObject; }
+
+    LineLayoutItem* operator->() { return this; }
+
+    LineLayoutItem parent() const;
+    LineLayoutItem nextSibling() const;
+    LineLayoutItem previousSibling() const;
+    LineLayoutItem slowFirstChild() const;
+    LineLayoutItem slowLastChild() const;
+
+    const ComputedStyle* style() const;
+    const ComputedStyle& styleRef() const;
+
+    Document& document() const;
+
+    bool preservesNewline() const;
+
+    unsigned length() const;
+
+    bool isFloatingOrOutOfFlowPositioned() const;
+    bool isFloating() const;
+    bool isOutOfFlowPositioned() const;
+    bool isBR() const;
+    bool isHorizontalWritingMode() const;
+    bool isImage() const;
+    bool isLayoutInline() const;
+    bool isListMarker() const;
+    bool isReplaced() const;
+    bool isRubyRun() const;
+    bool isSVGInlineText() const;
+    bool isTableCell() const;
+    bool isText() const;
+
+protected:
+    LayoutObject* layoutObject() { return m_layoutObject; }
+    const LayoutObject* layoutObject() const { return m_layoutObject; }
+
+    friend class LineLayoutBlockFlow; // for layoutObject
+    friend class LineLayoutBox;
+    friend class LineLayoutInline;
+    friend class LineLayoutText;
+
+private:
+    LayoutObject* m_layoutObject;
+};
+
+} // namespace blink
+
+#endif // LineLayoutItem_h