RFR: 7132413: [macosx] closed/javax/swing/AbstractButton/5049549/bug5049549.java fails on MacOS

[Prasanta Sadhukhan]

It was seen that some of the icons like disabled-selected:,  rollover icons are not shown.
Fixed to get the default selected icon and use that if in case the icon for that state is not set.

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Commit messages:
 - Fix showig proper icon

Changes: https://git.openjdk.org/jdk/pull/9481/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9481&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-7132413
  Stats: 19 lines in 1 file changed: 17 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/9481.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9481/head:pull/9481

PR: https://git.openjdk.org/jdk/pull/9481