<AWT Dev> RFR: 8198617: java/awt/Focus/6382144/EndlessLoopTest.java fails on mac

[Prasanta Sadhukhan]

This test was failing earlier in our nightly testing citing "java.lang.RuntimeException: java.awt.IllegalComponentStateException: component must be showing on the screen to determine its location "
Updated test to 
use swing components in EDT, 
setAutoDelay for mouse events, 
add a delay after frame is made visible,
move the frame to center of screen 
and dispose of the frame finally.

Several iterations of the test pass in all platforms. Link in JBS.

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Commit messages:
 - fix
 - 8198617: java/awt/Focus/6382144/EndlessLoopTest.java fails on mac

Changes: https://git.openjdk.java.net/jdk/pull/3614/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3614&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8198617
  Stats: 111 lines in 2 files changed: 47 ins; 36 del; 28 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3614.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3614/head:pull/3614

PR: https://git.openjdk.java.net/jdk/pull/3614