RFR: 8299553: Make ScaledEtchedBorderTest.java comprehensive [v2]

[Alisen Chung]

On Wed, 4 Jan 2023 16:26:24 GMT, Alexey Ivanov <aivanov at openjdk.org> wrote:

>> The `ScaledEtchedBorderTest.java` test ([JDK-8279614](https://bugs.openjdk.org/browse/JDK-8279614)) verifies that the thickness of lines of `EtchedBorder` is consistent. The component inside had the same background color as the frame. Yet if there's another component the background of which is different, that background could be seen.
>> 
>> The updated test covers the scenario reported in [JDK-8294921](https://bugs.openjdk.org/browse/JDK-8294921).
>> 
>> The bug itself is fixed by refactoring [JDK-8294680](https://bugs.openjdk.org/browse/JDK-8294680) the border rendering code which uses a more precise coordinate calculation, see #11571. Thus, I contribute the test under a separate bugid.
>> 
>> I also modified `ScaledLineBorderTest.java` so that the location of the child panels is saved when they're created as done in `ScaledTextFieldBorderTest.java` in #11498. I removed the unused `Component` import after this modification from both tests.
>
> Alexey Ivanov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Move State enum before checkBorder where it's used

Marked as reviewed by achung (Committer).

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

PR: https://git.openjdk.org/jdk/pull/11836