RFR: 8276794: Change nested classes in java.desktop to static nested classes [v2]

[Andrey Turbanov]

> Non-static classes hold a link to their parent classes, which in many cases can be avoided.
> I updated only private and package-private classes. Didn't touch public/protected to not break external code.
> Similar cleanup in java.base - [JDK-8261880](https://bugs.openjdk.java.net/browse/JDK-8261880)

Andrey Turbanov has updated the pull request incrementally with one additional commit since the last revision:

  [PATCH] Change nested classes in java.desktop to static nested classes
  fix review comments

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5943/files
  - new: https://git.openjdk.java.net/jdk/pull/5943/files/a9671a0e..1eeab86a

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5943&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5943&range=00-01

  Stats: 4 lines in 3 files changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5943.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5943/head:pull/5943

PR: https://git.openjdk.java.net/jdk/pull/5943