[OpenJDK 2D-Dev] RFR: 8226384: Implement a better logic to switch between OpenGL and Metal pipeline

[Jayathirth D V]

We have many if else conditions to select OpenGL/Metal pipeline objects.
Apart from initialization phase we should not fetch these objects everytime checking whether we are using OpenGL/Metal pipeline.

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Commit messages:
 - 8226384: Implement a better logic to switch between OpenGL and Metal pipeline

Changes: https://git.openjdk.java.net/jdk/pull/3851/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3851&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8226384
  Stats: 111 lines in 5 files changed: 57 ins; 42 del; 12 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3851.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3851/head:pull/3851

PR: https://git.openjdk.java.net/jdk/pull/3851