hg: kulla/dev/langtools: Per JShellTool review, switch EditPad's closeLock to CountDownLatch.

[robert.field at oracle.com]

Changeset: 5906e079b087
Author:    rfield
Date:      2015-09-08 14:40 -0700
URL:       http://hg.openjdk.java.net/kulla/dev/langtools/rev/5906e079b087

Per JShellTool review, switch EditPad's closeLock to CountDownLatch.

! src/jdk.jshell/share/classes/jdk/internal/jshell/tool/EditPad.java
! test/jdk/jshell/EditorPadTest.java