RFR: 8338306: WebView Drag and Drop fails with WebKit 619.1

[Hima Bindu Meda]

This commit resolves drag and drop issue observed with Webkit-619.1. Verified build on all platforms. No issue seen

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Commit messages:
 - Resolve DragandDrop issue

Changes: https://git.openjdk.org/jfx/pull/1538/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1538&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8338306
  Stats: 4 lines in 1 file changed: 3 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1538.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1538/head:pull/1538

PR: https://git.openjdk.org/jfx/pull/1538