<Swing Dev> RFR: 8233560: [TESTBUG] ToolTipManager/Test6256140.java is failing on macos

[Prasanta Sadhukhan]

Please review a test fix for a test issue seen to be failing on mach5 macos systems due to timing issue.
Modified the test to modify setAutoDelay() time, added delay() after frame is made visible, added waitForIdle() and also finally dispose of the frame.
Mach5 job has been run for several iterations in all platforms. Link in JBS.

-------------

Commit messages:
 - 8233560: [TESTBUG] ToolTipManager/Test6256140.java is failing on macos

Changes: https://git.openjdk.java.net/jdk/pull/901/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=901&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8233560
  Stats: 60 lines in 2 files changed: 23 ins; 15 del; 22 mod
  Patch: https://git.openjdk.java.net/jdk/pull/901.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/901/head:pull/901

PR: https://git.openjdk.java.net/jdk/pull/901