RFR: 8302268: Prefer ArrayList to LinkedList in XEmbeddedFramePeer

[Andrey Turbanov]

There is only add/iterator/indexOf calls on this list. No removes from the head or something like this. ArrayList should be preferred as more efficient and widely used (more chances for JIT) collection

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Commit messages:
 - [PATCH] Prefer ArrayList to LinkedList in XEmbeddedFramePeer

Changes: https://git.openjdk.org/jdk/pull/12486/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12486&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8302268
  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/12486.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12486/head:pull/12486

PR: https://git.openjdk.org/jdk/pull/12486