--- a/widget/gtk/nsWindow.cpp
+++ b/widget/gtk/nsWindow.cpp
@@ -215,16 +215,18 @@ static void     hierarchy_changed_cb    
                                            GtkWidget *previous_toplevel);
 static gboolean window_state_event_cb     (GtkWidget *widget,
                                            GdkEventWindowState *event);
 static void     theme_changed_cb          (GtkSettings *settings,
                                            GParamSpec *pspec,
                                            nsWindow *data);
 static void     check_resize_cb           (GtkContainer* container,
                                            gpointer user_data);
+static void     composited_changed_cb     (GtkWidget* widget,
+                                           gpointer user_data);
 
 #if (MOZ_WIDGET_GTK == 3)
 static void     scale_changed_cb          (GtkWidget* widget,
                                            GParamSpec* aPSpec,
                                            gpointer aPointer);
 #endif
 #if GTK_CHECK_VERSION(3,4,0)
 static gboolean touch_event_cb            (GtkWidget* aWidget,
@@ -3365,16 +3367,29 @@ nsWindow::OnDPIChanged()
 
 void
 nsWindow::OnCheckResize()
 {
     mPendingConfigures++;
 }
 
 void
+nsWindow::OnCompositedChanged()
+{
+  if (mWidgetListener) {
+    nsIPresShell* presShell = mWidgetListener->GetPresShell();
+    if (presShell) {
+      // Update CSD after the change in alpha visibility
+      presShell->ThemeChanged();
+    }
+  }
+  CleanLayerManagerRecursive();
+}
+
+void
 nsWindow::DispatchDragEvent(EventMessage aMsg, const LayoutDeviceIntPoint& aRefPoint,
                             guint aTime)
 {
     WidgetDragEvent event(true, aMsg, this);
 
     InitDragEvent(event);
 
     event.mRefPoint = aRefPoint;
@@ -3832,16 +3847,18 @@ nsWindow::Create(nsIWidget* aParent,
         g_signal_connect(mShell, "configure_event",
                          G_CALLBACK(configure_event_cb), nullptr);
         g_signal_connect(mShell, "delete_event",
                          G_CALLBACK(delete_event_cb), nullptr);
         g_signal_connect(mShell, "window_state_event",
                          G_CALLBACK(window_state_event_cb), nullptr);
         g_signal_connect(mShell, "check-resize",
                          G_CALLBACK(check_resize_cb), nullptr);
+        g_signal_connect(mShell, "composited-changed",
+                         G_CALLBACK(composited_changed_cb), nullptr);
 
         GtkSettings* default_settings = gtk_settings_get_default();
         g_signal_connect_after(default_settings,
                                "notify::gtk-theme-name",
                                G_CALLBACK(theme_changed_cb), this);
         g_signal_connect_after(default_settings,
                                "notify::gtk-font-name",
                                G_CALLBACK(theme_changed_cb), this);
@@ -5839,16 +5856,26 @@ check_resize_cb (GtkContainer* container
 {
     RefPtr<nsWindow> window = get_window_for_gtk_widget(GTK_WIDGET(container));
     if (!window) {
       return;
     }
     window->OnCheckResize();
 }
 
+static void
+composited_changed_cb (GtkWidget* widget, gpointer user_data)
+{
+    RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
+    if (!window) {
+      return;
+    }
+    window->OnCompositedChanged();
+}
+
 #if (MOZ_WIDGET_GTK == 3)
 static void
 scale_changed_cb (GtkWidget* widget, GParamSpec* aPSpec, gpointer aPointer)
 {
     RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
     if (!window) {
       return;
     }
@@ -6439,17 +6466,20 @@ nsWindow::GetLayerManager(PLayerTransact
                           LayersBackend aBackendHint,
                           LayerManagerPersistence aPersistence)
 {
     if (mIsDestroyed) {
       // Prevent external code from triggering the re-creation of the LayerManager/Compositor
       // during shutdown. Just return what we currently have, which is most likely null.
       return mLayerManager;
     }
-    if (!mLayerManager && eTransparencyTransparent == GetTransparencyMode()) {
+
+    if (!mLayerManager &&
+        eTransparencyTransparent == GetTransparencyMode())
+    {
         mLayerManager = CreateBasicLayerManager();
     }
 
     return nsBaseWidget::GetLayerManager(aShadowManager, aBackendHint, aPersistence);
 }
 
 void
 nsWindow::ClearCachedResources()
@@ -6748,8 +6778,22 @@ void nsWindow::GetCompositorWidgetInitDa
 {
   #ifdef MOZ_X11
   *aInitData = mozilla::widget::CompositorWidgetInitData(
                                   mXWindow,
                                   nsCString(XDisplayString(mXDisplay)),
                                   GetClientSize());
   #endif
 }
+
+bool
+nsWindow::IsComposited() const
+{
+  if (!mGdkWindow) {
+    NS_WARNING("nsWindow::HasARGBVisual called before realization!");
+    return false;
+  }
+
+  GdkScreen* gdkScreen = gdk_screen_get_default();
+  return gdk_screen_is_composited(gdkScreen) &&
+         (gdk_window_get_visual(mGdkWindow)
+            == gdk_screen_get_rgba_visual(gdkScreen));
+}

--- a/widget/gtk/nsWindow.h
+++ b/widget/gtk/nsWindow.h
@@ -246,16 +246,17 @@ private:
     void               ReleaseGrabs (void);
 
     void               UpdateClientOffset();
 
 public:
     void               ThemeChanged(void);
     void               OnDPIChanged(void);
     void               OnCheckResize(void);
+    void               OnCompositedChanged(void);
 
 #ifdef MOZ_X11
     Window             mOldFocusWindow;
 #endif /* MOZ_X11 */
 
     static guint32     sLastButtonPressTime;
 
     virtual MOZ_MUST_USE nsresult
@@ -425,16 +426,18 @@ private:
       CheckForRollup(0, 0, false, true);
     }
 
     bool               GetDragInfo(mozilla::WidgetMouseEvent* aMouseEvent,
                                    GdkWindow** aWindow, gint* aButton,
                                    gint* aRootX, gint* aRootY);
     void               ClearCachedResources();
     nsIWidgetListener* GetListener();
+    bool               IsComposited() const;
+
 
     GtkWidget          *mShell;
     MozContainer       *mContainer;
     GdkWindow          *mGdkWindow;
 
     uint32_t            mHasMappedToplevel : 1,
                         mIsFullyObscured : 1,
                         mRetryPointerGrab : 1;