8.0-controls-scrum-569: 42% performance regression in Controls.ListView-Keyboard

There is -42% (-53 fps) Controls.ListView-Keyboard performance regression in build 8.0-controls-scrum-569.
This build contains only one change (according to Hudson):
 
1. RT-19435: follow styleable parent chain to find parent stylesheets and inline styles.


According to JPA profiles there is significant increase of time spent in
 javafx.collections.WeakSetChangeListener.onChange(...)
 
 
The time spent in GC also increased from 1.2 sec to 4.9 sec (total exec time is 30 sec).

Steps to run Controls.ListView-Keyboard:
> cd JFX_WS/tests/performance/Controls/
> ant
> java -Djavafx.animation.fullspeed=true
       -cp "JFX_HOME/rt/lib/ext/jfxrt.jar;./dist/Controls.jar;../FXBenchmark/dist/FXBenchmark.jar;../../../import/benchmarks-2.1.1/benchmarks-2.1.1.jar"
       jrockit.bm.Main controls.bm.ListViewBenchmark -i 1 -wt 0 -tr 60 -cells 10000 -mode keyboard -keysPerInjection 100