RFR: 8361188: Test java/awt/Mixing/AWT_Mixing/JComboBoxOverlapping.java fails on Mac OS X

[Khalid Boulanouare]

Fixed an issue where null value component is not checked in class java/awt/Mixing/AWT_Mixing/OverlappingTestBase.

Also removed test java/awt/Mixing/AWT_Mixing/JComboBoxOverlapping.java from problem list file.

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Depends on: https://git.openjdk.org/jdk/pull/25971

Commit messages:
 - Merge branch 'pr/25971' into jdk-8361188
 - Merge branch 'pr/25971' into jdk-8361188
 - Merge branch 'openjdk:master' into jdk-8361188
 - Removes test from Problem List
 - Returns false if component is null, in the case of embedded frame

Changes: https://git.openjdk.org/jdk/pull/26162/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26162&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8361188
  Stats: 3 lines in 2 files changed: 1 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/26162.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26162/head:pull/26162

PR: https://git.openjdk.org/jdk/pull/26162