RFR: 8306119: Many components respond to a mouse event by requesting focus without supplying the MOUSE_EVENT cause [v3]

[Prasanta Sadhukhan]

> Many Swing components request a focus transfer in response to a mouse event, but fail to supply a Cause when requesting focus. A focus event listener will find the cause to be UNKNOWN, but MOUSE_EVENT would be more appropriate. 
> Fixed by adding MOUSE_EVENT cause to requestFocus() when it is called for mouse events...
> 
> All jtreg/jck tests are ok..

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

  test fix

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/14004/files
  - new: https://git.openjdk.org/jdk/pull/14004/files/1118436f..ee4afbbd

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14004&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14004&range=01-02

  Stats: 10 lines in 1 file changed: 0 ins; 1 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/14004.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14004/head:pull/14004

PR: https://git.openjdk.org/jdk/pull/14004