Remove Cairo-specific code

src/ManagedShell.AppBar/AppBarManager.cs

@@ -19,7 +19,6 @@ public class AppBarManager : IDisposable
 
         public List<AppBarWindow> AppBars { get; } = new List<AppBarWindow>();
         public List<AppBarWindow> AutoHideBars { get; } = new List<AppBarWindow>();
-        public EventHandler<AppBarEventArgs> AppBarEvent;
 
         public AppBarManager(ExplorerHelper explorerHelper)
         {
@@ -37,12 +36,6 @@ public void SignalGracefulShutdown()
             }
         }
 
-        public void NotifyAppBarEvent(AppBarWindow sender, AppBarEventReason reason)
-        {
-            AppBarEventArgs args = new AppBarEventArgs { Reason = reason };
-            AppBarEvent?.Invoke(sender, args);
-        }
-
         private IntPtr appBarMessageDelegate(APPBARMSGDATAV3 amd, ref bool handled)
         {
             // only handle certain messages, send other AppBar messages to default handler

src/ManagedShell.AppBar/AppBarWindow.cs

@@ -565,11 +565,6 @@ protected virtual IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lPa
                 ProcessScreenChange(ScreenSetupReason.DeviceChange);
                 handled = true;
             }
-            else if (msg == (int)NativeMethods.WM.DWMCOMPOSITIONCHANGED)
-            {
-                ProcessScreenChange(ScreenSetupReason.DwmChange);
-                handled = true;
-            }
 
             return IntPtr.Zero;
         }

src/ManagedShell.AppBar/ScreenSetupReason.cs

@@ -4,9 +4,6 @@ public enum ScreenSetupReason
     {
         DeviceChange,
         DisplayChange,
-        DpiChange,
-        DwmChange,
-        FirstRun,
-        Reconciliation
+        DpiChange
     }
 }