RFR: 8360498: [TEST_BUG] Some Mixing test continue to fail [v12]

[Khalid Boulanouare]

> This PR will consolidate fixes of the following bugs:
> 
> https://bugs.openjdk.org/browse/JDK-8361188
> https://bugs.openjdk.org/browse/JDK-8361189
> https://bugs.openjdk.org/browse/JDK-8361190
> https://bugs.openjdk.org/browse/JDK-8361191
> https://bugs.openjdk.org/browse/JDK-8361192
> https://bugs.openjdk.org/browse/JDK-8361193
> https://bugs.openjdk.org/browse/JDK-8361195
> 
> This PR depends on https://github.com/openjdk/jdk/pull/25971
> 
> For test : java/awt/Mixing/AWT_Mixing/JComboBoxOverlapping.java, the fix suggested is to return false in method isValidForPixelCheck for embedded frame, in which case the component is set to null. For more details see bug: [JDK-8361188](https://bugs.openjdk.org/browse/JDK-8361188)
> 
> For test : test/jdk/java/awt/Mixing/AWT_Mixing/MixingPanelsResizing.java, I had to create a a tolerance color matching method for mac for the tests to pass. Also, the jbuttons needed to have different color than the color of the background frame, in order for test to pass. For more detail see bug: https://bugs.openjdk.org/browse/JDK-8361193
> 
> For test : test/jdk/java/awt/Mixing/AWT_Mixing/JSplitPaneOverlapping.java, it seems that color selected for lightweight component matches the background color of the frame. And this will cause the test to fail when matching colors. Choosing any color different than the background color will get the test to pass. For more details, see bug: https://bugs.openjdk.org/browse/JDK-8361192
> 
> For test test/jdk/java/awt/Mixing/AWT_Mixing/JPopupMenuOverlapping.java, it looks like the frame when visible, the popup test does not work properly. The frame needs to be hidden for the test to click on popup. For more details see bug: https://bugs.openjdk.org/browse/JDK-8361191
> 
> For test test/jdk/java/awt/Mixing/AWT_Mixing/JMenuBarOverlapping.java, the test runs successfully but it times out after the default 2 minutes of jtreg. increasing the timeout to 3 minutes get the test to pass. For more details please refer to bug: https://bugs.openjdk.org/browse/JDK-8361190

Khalid Boulanouare has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 67 additional commits since the last revision:

 - Merge branch 'pr/25971' into jdk-8360498
 - Merge branch 'openjdk:master' into jdk-8158801
 - Centers missed frames in the middle of screen
 - Uses KeyboardFocusManager instead of FocusManager
 - Reverted not needed changes
 - Updates copyright years
 - Merge branch 'openjdk:master' into jdk-8158801
 - Centers frames in the middle of the screen
 - Merge branch 'openjdk:master' into jdk-8360498
 - Merge branch 'pr/25971' into jdk-8360498
 - ... and 57 more: https://git.openjdk.org/jdk/compare/ea0b50e2...ce0d3527

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/26625/files
  - new: https://git.openjdk.org/jdk/pull/26625/files/ecf7d3cf..ce0d3527

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26625&range=11
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26625&range=10-11

  Stats: 12173 lines in 474 files changed: 7460 ins; 3042 del; 1671 mod
  Patch: https://git.openjdk.org/jdk/pull/26625.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26625/head:pull/26625

PR: https://git.openjdk.org/jdk/pull/26625