DK: b15
OS: Ubuntu 14.04

The test makes other tests unstable.
The test fails from time to times with an exception because of thread race.

Cause: the test tries to render an image when the frame is disposed or is not visible yet.
Suggested fix: the main thread should wait for the frame becomes visible and for the completion of rendering thread(BallThread) and dispose the frame after that.

java.lang.IllegalStateException: Component must have a valid peer at java.awt.Component$FlipBufferStrategy.createBuffers(Component.java:4009) at java.awt.Component$FlipBufferStrategy.revalidate(Component.java:4159) at java.awt.Component$FlipBufferStrategy.revalidate(Component.java:4150) at java.awt.Component$FlipBufferStrategy.getDrawGraphics(Component.java:4142) at AltTabCrashTest.renderToBS(AltTabCrashTest.java:359) at AltTabCrashTest$BallThread.run(AltTabCrashTest.java:193)

java.lang.NullPointerException at java.awt.Component$FlipBufferStrategy.createBuffers(Component.java:4043) at java.awt.Component$FlipBufferStrategy.revalidate(Component.java:4159) at java.awt.Component$FlipBufferStrategy.revalidate(Component.java:4150) at java.awt.Component$FlipBufferStrategy.getDrawGraphics(Component.java:4142) at AltTabCrashTest.renderToBS(AltTabCrashTest.java:359) at AltTabCrashTest$BallThread.run(AltTabCrashTest.java:193)

closed/java/awt/FullScreen/AltTabCrashTest/AltTabCrashTest.java
java/awt/FullScreen/AltTabCrashTest/AltTabCrashTest.java (the test was moved to open in jdk9.client, the test should be fixed in this repo)