This PR removes the usage of AppContext from the GraphicsDevice class. The original use case was to store the full-screen window in some AppContext, which was necessary in the context of plugin/appletviewer environments. However, there is now effectively only one main AppContext, so this indirection can be eliminated.
Notes: GraphicsDevice provides two methods for handling full-screen windows: - setFullScreenWindow() is considered thread-safe, as all platform-specific implementations override it with synchronized methods ([example](https://github.com/openjdk/jdk/blob/23e1e2ff4a4a75ec268c7925fb98d6b96a01bbcf/src/java.desktop/macosx/classes/sun/awt/CGraphicsDevice.java#L226)). - getFullScreenWindow() previously relied on AppContext for thread-safety. After removing AppContext, this method is now made thread-safe by declaring the fullScreenWindow field as volatile. This change has been validated by an added test. ------------- Commit messages: - Create FullScreenWindowRace.java - 8359266: Delete the usage of AppContext in the GraphicsDevice Changes: https://git.openjdk.org/jdk/pull/25818/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25818&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8359266 Stats: 93 lines in 2 files changed: 65 ins; 23 del; 5 mod Patch: https://git.openjdk.org/jdk/pull/25818.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/25818/head:pull/25818 PR: https://git.openjdk.org/jdk/pull/25818
