Put transform tree building in DisplayItemPropertyTreeBuilder.

Source/platform/exported/WebDisplayItemClipTree.cpp

+// 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 "public/platform/WebDisplayItemClipTree.h"
+
+#include "platform/graphics/paint/DisplayItemClipTree.h"
+
+namespace blink {
+
+WebDisplayItemClipTree::WebDisplayItemClipTree()
+{
+}
+
+WebDisplayItemClipTree::WebDisplayItemClipTree(const PassOwnPtr<DisplayItemClipTree>& passImpl)
+    : m_private(passImpl)
+{
+}
+
+WebDisplayItemClipTree::~WebDisplayItemClipTree()
+{
+    // WebPrivateOwnPtr requires explicit clearing here.
+    m_private.reset(nullptr);
+}
+
+size_t WebDisplayItemClipTree::nodeCount() const
+{
+    return m_private->nodeCount();
+}
+
+const WebDisplayItemClipTree::ClipNode& WebDisplayItemClipTree::nodeAt(size_t index) const
+{
+    return m_private->nodeAt(index);
+}
+
+} // namespace blink