RFR: 8242106: [macos] Remove obsolete GlassView2D.m class

[Kevin Rushforth]

This is a simple fix to remove some obsolete code. As noted in the JBS description, GlassView2D was made obsolete back
in JDK 8, but the GlassView2D.m / .h class files were left in the repo. It is dead code, as there are no references to
that class.

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Commit messages:
 - 8242106: [macos] Remove obsolete GlassView2D.m class

Changes: https://git.openjdk.java.net/jfx/pull/162/files
 Webrev: https://webrevs.openjdk.java.net/jfx/162/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8242106
  Stats: 460 lines in 3 files changed: 0 ins; 460 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/162.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/162/head:pull/162

PR: https://git.openjdk.java.net/jfx/pull/162