RFR: 8360498: [TEST_BUG] Some Mixing test continue to fail [v7]

[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 149 additional commits since the last revision:

 - Revert "Accept color differences to less or equal to 15"
   
   This reverts commit a98db3e22781088eccd95912697853355f22645e.
 - Accept color differences to less or equal to 15
 - Changes the look and feel to the default Metal
 - Removes setOpqaue for swing buttons
 - Renames color tolerance for macosx
 - Uses simplified statement in method isAlmostEqualColor
 - Adds space around binary operators
 - Merge branch 'openjdk:master' into jdk-8360498
 - 8364723: Sort share/interpreter includes
   
   Reviewed-by: shade, ayang
 - 8365244: Some test control variables are undocumented in doc/testing.md
   
   Reviewed-by: erikj
 - ... and 139 more: https://git.openjdk.org/jdk/compare/47ff0eb6...c748b77f

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/26625/files
  - new: https://git.openjdk.org/jdk/pull/26625/files/85f9321f..c748b77f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26625&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26625&range=05-06

  Stats: 20034 lines in 564 files changed: 10513 ins; 7299 del; 2222 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