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diff --git a/widget/gtk/WaylandVsyncSource.h b/widget/gtk/WaylandVsyncSource.h
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+++ b/widget/gtk/WaylandVsyncSource.h
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+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef _WaylandVsyncSource_h_
+#define _WaylandVsyncSource_h_
+
+#include "mozilla/RefPtr.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/Monitor.h"
+#include "MozContainer.h"
+#include "VsyncSource.h"
+#include "base/thread.h"
+#include "nsWaylandDisplay.h"
+
+namespace mozilla {
+
+/*
+ * WaylandVsyncSource
+ *
+ * This class provides a per-widget VsyncSource under Wayland, emulated using
+ * frame callbacks on the widget surface with empty surface commits.
+ *
+ * Wayland does not expose vsync/vblank, as it considers that an implementation
+ * detail the clients should not concern themselves with. Instead, frame
+ * callbacks are provided whenever the compositor believes it is a good time to
+ * start drawing the next frame for a particular surface, giving us as much
+ * time as possible to do so.
+ *
+ * Note that the compositor sends frame callbacks only when it sees fit, and
+ * when that may be is entirely up to the compositor. One cannot expect a
+ * certain rate of callbacks, or any callbacks at all. Examples of common
+ * variations would be surfaces moved between outputs with different refresh
+ * rates, and surfaces that are hidden and therefore do not receieve any
+ * callbacks at all. Other hypothetical scenarios of variation could be
+ * throttling to conserve power, or because a user has requested it.
+ *
+ */
+class WaylandVsyncSource final : public gfx::VsyncSource {
+ public:
+  explicit WaylandVsyncSource(MozContainer* container) {
+    MOZ_ASSERT(NS_IsMainThread());
+    mGlobalDisplay = new WaylandDisplay(container);
+  }
+
+  virtual ~WaylandVsyncSource() { MOZ_ASSERT(NS_IsMainThread()); }
+
+  virtual Display& GetGlobalDisplay() override { return *mGlobalDisplay; }
+
+  class WaylandDisplay final : public mozilla::gfx::VsyncSource::Display {
+   public:
+    explicit WaylandDisplay(MozContainer* container);
+
+    void EnableMonitor();
+    void DisableMonitor();
+
+    void FrameCallback(uint32_t timestampTime);
+    void Notify();
+
+    TimeDuration GetVsyncRate() override;
+
+    virtual void EnableVsync() override;
+
+    virtual void DisableVsync() override;
+
+    virtual bool IsVsyncEnabled() override;
+
+    virtual void Shutdown() override;
+
+   private:
+    virtual ~WaylandDisplay() = default;
+    void Refresh();
+    void SetupFrameCallback();
+    void ClearFrameCallback();
+    void CalculateVsyncRate(TimeStamp vsyncTimestamp);
+
+    Mutex mEnabledLock;
+    bool mIsShutdown;
+    bool mVsyncEnabled;
+    bool mMonitorEnabled;
+    struct wl_display* mDisplay;
+    struct wl_callback* mCallback;
+    MozContainer* mContainer;
+    TimeDuration mVsyncRate;
+    TimeStamp mLastVsyncTimeStamp;
+  };
+
+ private:
+  // We need a refcounted VsyncSource::Display to use chromium IPC runnables.
+  RefPtr<WaylandDisplay> mGlobalDisplay;
+};
+
+}  // namespace mozilla
+
+#endif  // _WaylandVsyncSource_h_