test/java/awt/Modal/ModalInternalFrameTest/ModalInternalFrameTest.java

rev 14031 : 8160974: [TESTBUG] Mark more headful tests with @key headful.

This is a backport of fe58d505fffd from jdk9. 228/596 hunks apply without
modifications. 16 hunks required manual rework. The remainder were for files
not present in jdk8u.

*** 21,30 ****
--- 21,31 ----
   * questions.
   */
  
  /*
    @test
+   @key headful
    @bug 6518753
    @summary Tests the functionality of modal Swing internal frames
    @author artem.ananiev: area=awt.modal
    @run main/timeout=30 ModalInternalFrameTest
  */