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diff --git a/src/core/compositor/compositor.h b/src/core/compositor/compositor.h
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+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtWebEngine module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef COMPOSITOR_H
+#define COMPOSITOR_H
+
+#include <base/memory/weak_ptr.h>
+#include <components/viz/common/frame_sinks/begin_frame_source.h>
+#include <components/viz/common/quads/compositor_frame.h>
+
+#include <QtCore/qglobal.h>
+#include <QtCore/qshareddata.h>
+
+#include <QtCore/qglobal.h>
+#include <QtCore/qshareddata.h>
+
+QT_BEGIN_NAMESPACE
+class QSGNode;
+QT_END_NAMESPACE
+
+namespace content {
+class RenderWidgetHost;
+}
+namespace viz {
+struct ReturnedResource;
+namespace mojom {
+class CompositorFrameSinkClient;
+} // namespace mojom
+} // namespace viz
+
+namespace QtWebEngineCore {
+
+class CompositorResourceTracker;
+class RenderWidgetHostViewQtDelegate;
+
+// Receives viz::CompositorFrames from child compositors and provides QSGNodes
+// to the Qt Quick renderer.
+//
+// The life cycle of a frame:
+//
+//   Step 1. A new CompositorFrame is received from child compositors and handed
+//   off to submitFrame(). The new frame will start off in a pending state.
+//
+//   Step 2. Once the new frame is ready to be rendered, Compositor will notify
+//   the client by running the callback given to submitFrame().
+//
+//   Step 3. Once the client is ready to render, updatePaintNode() should be
+//   called to receive the scene graph for the new frame. This call will commit
+//   the pending frame. Until the next frame is ready, all subsequent calls to
+//   updatePaintNode() will keep using this same committed frame.
+//
+//   Step 4. The Compositor will return unneeded resources back to the child
+//   compositors. Go to step 1.
+class Compositor final : private viz::BeginFrameObserverBase
+{
+public:
+    explicit Compositor(content::RenderWidgetHost *host);
+    ~Compositor() override;
+
+    void setFrameSinkClient(viz::mojom::CompositorFrameSinkClient *frameSinkClient);
+    void setNeedsBeginFrames(bool needsBeginFrames);
+
+    void submitFrame(viz::CompositorFrame frame, base::OnceClosure callback);
+    QSGNode *updatePaintNode(QSGNode *oldNode, RenderWidgetHostViewQtDelegate *viewDelegate);
+
+private:
+    void runSubmitCallback();
+    void notifyFrameCommitted();
+    void sendPresentationFeedback(uint frame_token);
+
+    // viz::BeginFrameObserverBase
+    bool OnBeginFrameDerivedImpl(const viz::BeginFrameArgs &args) override;
+    void OnBeginFrameSourcePausedChanged(bool paused) override;
+
+    viz::CompositorFrame m_committedFrame;
+    viz::CompositorFrame m_pendingFrame;
+    base::OnceClosure m_submitCallback;
+    std::unique_ptr<CompositorResourceTracker> m_resourceTracker;
+    content::RenderWidgetHost *m_host;
+    std::unique_ptr<viz::SyntheticBeginFrameSource> m_beginFrameSource;
+    viz::mojom::CompositorFrameSinkClient *m_frameSinkClient = nullptr;
+    bool m_updatePaintNodeShouldCommit = false;
+    bool m_needsBeginFrames = false;
+
+    scoped_refptr<base::SingleThreadTaskRunner> m_taskRunner;
+    base::WeakPtrFactory<Compositor> m_weakPtrFactory{this};
+
+    DISALLOW_COPY_AND_ASSIGN(Compositor);
+};
+
+} // namespace QtWebEngineCore
+
+#endif // !COMPOSITOR_H