Implement 'will-change' parsing

Source/core/rendering/style/StyleWillChangeData.cpp

+// Copyright 2014 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/rendering/style/StyleWillChangeData.h"
+
+namespace WebCore {
+
+StyleWillChangeData::StyleWillChangeData()
+    : m_contents(false)
+    , m_scrollPosition(false)
+{
+}
+
+StyleWillChangeData::StyleWillChangeData(const StyleWillChangeData& o)
+    : RefCounted<StyleWillChangeData>()
+    , m_properties(o.m_properties)
+    , m_contents(o.m_contents)
+    , m_scrollPosition(o.m_scrollPosition)
+{
+}
+
+} // namespace WebCore