<AWT Dev> RFR: 8259779: Create implementation for NSAccessibilityStepper protocol

[Pankaj Bansal]

Creating a native peer for stepper/spinner accessibility role on Max OS X.

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Commit messages:
 - Resolve some whitespaces issues
 - 8259779: Create implementation for NSAccessibilityStepper protocol

Changes: https://git.openjdk.java.net/jdk/pull/2081/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2081&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8259779
  Stats: 115 lines in 3 files changed: 114 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2081.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2081/head:pull/2081

PR: https://git.openjdk.java.net/jdk/pull/2081