RFR: 8269115: WebView paste event contains old data [v4]

[Jay Bhaskar]

> Issue: The DataObject uses m_availMimeTypes as Vector of strings, and appending mime types in pasteboard operation like setPlainText, Hence it will append duplicate mime types in m_availMimeTypes , in this case the length clipboardData.types would be wrong, and duplicates data would be copied to clipboard target.
> Solution: Use ListHashSet data Structure instead of Vector for m_availMimeTypes.

Jay Bhaskar has updated the pull request incrementally with one additional commit since the last revision:

  Test regression according to bug

-------------

Changes:
  - all: https://git.openjdk.java.net/jfx/pull/729/files
  - new: https://git.openjdk.java.net/jfx/pull/729/files/d4da4ee5..dded44a5

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jfx&pr=729&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jfx&pr=729&range=02-03

  Stats: 31 lines in 1 file changed: 13 ins; 4 del; 14 mod
  Patch: https://git.openjdk.java.net/jfx/pull/729.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/729/head:pull/729

PR: https://git.openjdk.java.net/jfx/pull/729