8219636: Windows build failure after JDK-8207070 8u backport

Reviewed-by: zgu

src/windows/classes/sun/awt/windows/WToolkit.java

@@ -45,6 +45,7 @@ import javax.swing.text.JTextComponent;
 import sun.awt.AppContext;
 import sun.awt.AWTAccessor;
 import sun.awt.AWTAutoShutdown;
+import sun.awt.DisplayChangedListener;
 import sun.awt.LightweightFrame;
 import sun.awt.SunToolkit;
 import sun.misc.ThreadGroupUtils;