RFR: 8315825: Open some swing tests [v3]

[Alisen Chung]

> Opening some swing tests:
> 1 javax/swing/LayoutComparator/4907772/bug4907772.java
> 2 javax/swing/LayoutComparator/4979794/bug4979794.java
> 3 javax/swing/LegacyGlueFocusTraversalPolicy/4765272/bug4765272.java
> 4 javax/swing/RootPaneChecking/RootPaneChecking.java

Alisen Chung has updated the pull request incrementally with one additional commit since the last revision:

  extra newline at EOF

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15830/files
  - new: https://git.openjdk.org/jdk/pull/15830/files/345185ba..5ec823c3

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15830&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15830&range=01-02

  Stats: 3 lines in 3 files changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/15830.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15830/head:pull/15830

PR: https://git.openjdk.org/jdk/pull/15830