JBR-6316 Wayland: WLSMSurfaceData.getReplacement() throws UOE

Also fixed the keyboard repeat manager so that it does not prevent
application from shutting down.
Also improved fullscreen support.

src/java.desktop/unix/classes/sun/awt/wl/WLGraphicsDevice.java

@@ -219,9 +219,15 @@ public void setFullScreenWindow(Window w) {
             return;
         }
 
+        boolean fsSupported = isFullScreenSupported();
+        if (fsSupported && old != null) {
+            // enter windowed mode and restore original display mode
+            exitFullScreenExclusive(old);
+        }
+
         super.setFullScreenWindow(w);
 
-        if (isFullScreenSupported()) {
+        if (fsSupported) {
             if (w != null) {
                 enterFullScreenExclusive(w);
             } else {

src/java.desktop/unix/classes/sun/awt/wl/WLKeyboard.java

@@ -38,7 +38,7 @@ class WLKeyboard {
     }
 
     private class KeyRepeatManager {
-        private final Timer timer = new Timer();
+        private final Timer timer = new Timer("WLKeyboard.KeyRepeatManager", true);
         private TimerTask currentRepeatTask;
         private int delayBeforeRepeatMillis = 500;
         private int delayBetweenRepeatMillis = 50;

src/java.desktop/unix/classes/sun/java2d/wl/WLSMSurfaceData.java

@@ -80,7 +80,12 @@ public static WLSMSurfaceData createData(WLComponentPeer peer, WLSMGraphicsConfi
 
     @Override
     public SurfaceData getReplacement() {
-        throw new UnsupportedOperationException("Not implemented yet");
+        // It does not seem possible in Wayland to get your window's surface
+        // change mid-flight such that it needs a replacement.
+        // The only scenario when a surface gets forcibly invalidated is
+        // after WLComponentPeer.dispose(), at which point the surface
+        // is no longer needed anyway.
+        return null;
     }
 
     @Override