RFR: 8306943: Open source several dnd AWT tests [v2]

[Alexander Zvegintsev]

> Open sourcing few more tests:
> 
> java/awt/dnd/DnDAWTLockTest/DnDAWTLockTest.java
> java/awt/dnd/DragGestureInvokeLaterTest/DragGestureInvokeLaterTest.java
> java/awt/dnd/DragOverDropTargetPerformanceTest/DragOverDropTargetPerformanceTest.java
> java/awt/dnd/DragSourceDragEventModifiersTest/DragSourceDragEventModifiersTest.java
> java/awt/dnd/DragSourceGCrashTest/DragSourceGCrashTest.java
> 
> 
> Testing looks good.

Alexander Zvegintsev has updated the pull request incrementally with one additional commit since the last revision:

  add volatile

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13752/files
  - new: https://git.openjdk.org/jdk/pull/13752/files/b0cdf45f..ec43740f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13752&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13752&range=00-01

  Stats: 6 lines in 2 files changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/13752.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13752/head:pull/13752

PR: https://git.openjdk.org/jdk/pull/13752