RFR: 8290399: [macos] Aqua LAF does not fire an action event if combo box menu is displayed [v2]

[Prasanta Sadhukhan]

> When the user types Enter in an editable combo box, Aqua LAF fails to fire an action event if the menu is displayed.
> It seems actionEvent is fired when popup menu is not visible. 
> Fix is to make sure ActionEvent is fired irrespective of popup visiblity as is done in other L&F 
> (for ex, in MetalL&F it calls "ENTER", JTextField.notifyAction, where it calls postActionEvent irrespectively)
> https://github.com/openjdk/jdk/blob/master/src/java.desktop/share/classes/javax/swing/JTextField.java#L856

Prasanta Sadhukhan has updated the pull request incrementally with one additional commit since the last revision:

  Test made for macos

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9551/files
  - new: https://git.openjdk.org/jdk/pull/9551/files/d333df8f..0af01364

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9551&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9551&range=00-01

  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/9551.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9551/head:pull/9551

PR: https://git.openjdk.org/jdk/pull/9551