RFR: 8306137: Open source several AWT ScrollPane related tests [v5]

[Tejesh R]

> Open source few AWT ScrollPane related tests.

Tejesh R has updated the pull request incrementally with one additional commit since the last revision:

  Updated based on review comments

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Changes:
  - all: https://git.openjdk.org/jdk/pull/13621/files
  - new: https://git.openjdk.org/jdk/pull/13621/files/99fb2c73..d9bfe956

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13621&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13621&range=03-04

  Stats: 42 lines in 5 files changed: 8 ins; 22 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/13621.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13621/head:pull/13621

PR: https://git.openjdk.org/jdk/pull/13621