hg: openjfx/8u-dev/rt: 8172847: [macos] If you hit the escape key repeatedly to close the subwindow, the process crashes

[alexander.zvegintsev at oracle.com]

Changeset: e0d57a5a1c10
Author:    azvegint
Date:      2017-06-13 22:23 +0530
URL:       http://hg.openjdk.java.net/openjfx/8u-dev/rt/rev/e0d57a5a1c10

8172847: [macos] If you hit the escape key repeatedly to close the subwindow, the process crashes
Reviewed-by: kcr

! modules/graphics/src/main/native-glass/mac/GlassTouches.m