<AWT Dev> [8] Review Request: 8001472 api/java_awt/Window/indexTGF_* tests fail because expected colors aren't equal

[Sergey Bylokhov]

Hello.
Please review the fix for jdk 8.
According to the documentation of XSetWindowBackground [1]:
"Changing the background does not cause the window contents to be 
changed. To repaint the window and its background, use XClearWindow."

This error has big history as it was unstable. The behavior changes from 
update2update depending on that we generated UPDATE event or not, because
by default Container.update in distinguishing from Container.paint does 
clearRect().
After 7090424 we began to generate less paints and a problem became more 
visible.

[1] http://www.kodkast.com/unix-command/XSetWindowBackground

Bug: https://bugs.openjdk.java.net/browse/JDK-8001472
Webrev can be found at: http://cr.openjdk.java.net/~serb/8001472/webrev.00

-- 
Best regards, Sergey.