html_viewer/Mandoline: Avoid subclassing WebLayerImpl

components/html_viewer/web_layer_impl.h

-// 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 COMPONENTS_HTML_VIEWER_WEB_LAYER_IMPL_H_
-#define COMPONENTS_HTML_VIEWER_WEB_LAYER_IMPL_H_
-
-#include <utility>
-
-#include "cc/blink/web_layer_impl.h"
-#include "cc/layers/surface_layer.h"
-
-namespace mus {
-class View;
-}
-
-namespace html_viewer {
-
-class WebLayerImpl : public cc_blink::WebLayerImpl {
- public:
-  WebLayerImpl(mus::View* view, float device_pixel_ratio);
-  ~WebLayerImpl() override;
-
-  // WebLayer implementation.
-  void setBounds(const blink::WebSize& bounds) override;
-
- private:
-  mus::View* view_;
-  const float device_pixel_ratio_;
-  scoped_refptr<cc::SurfaceLayer> layer_;
-
-  DISALLOW_COPY_AND_ASSIGN(WebLayerImpl);
-};
-
-}  // namespace html_viewer
-
-#endif  // COMPONENTS_HTML_VIEWER_WEB_LAYER_IMPL_H_