8.0-controls-scrum-749: up to 55% performance regression in Controls.TextArea.v_scroll-255x1000-wrap

There is up to 55% performance regression in Controls.TextArea.v_scroll-255x1000-wrap in build 8.0-b106.
The regression first appeared in build 8.0-controls-scrum-749 which contains:
   1. RT-31901 - Regression: scrollbar issue with TitledPane
   2. RT-32654 : ScrollPane - remove DOS line endings, no code changed

JPA profiles show the time spent in javafx.scene.Scene.doLayoutPass() has been
increased from 0,148 sec to 26,760 sec (total test time is 30 secs). This is because
most of the time is now spent in com.sun.javafx.scene.control.skin.ScrollPaneSkin.layoutChildren.


Steps to run Controls.TextArea.v_scroll-255x1000-wrap
> 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.TextAreaBenchmark -i 1 -wt 0 -tr 60 -line-len 255 -line-num 1000 -mode V_SCROLL -wrap-text true