8303904: [macos]Transparent Windows Paint Wrong (Opaque, Pixelated) w/o Volatile Buffering
------------- Commit messages: - fix for pixelated images - Add test for pixelated images at high resolution - Test for Mac platfotm - Unit Test to Verify Window Transparency and Black Border Presence - fix 1 : fix for non-transparency and black borders Changes: https://git.openjdk.org/jdk/pull/23430/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23430&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8303904 Stats: 244 lines in 4 files changed: 237 ins; 0 del; 7 mod Patch: https://git.openjdk.org/jdk/pull/23430.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/23430/head:pull/23430 PR: https://git.openjdk.org/jdk/pull/23430
