[Rev 01] RFR: 8244647: Wrong first layout pass of Scrollbar controls on touch supported devices

[Jose Pereda]

> There is a visual glitch when the scrollbar controls are laid out on touch enabled devices.
> 
> The first time they are laid out in the wrong location (20 px from right or bottom), while the next passes are correct
> (8 px from right or bottom).
> The reason for this glitch is the use of `getWidth()` or `getHeight()` in the `resizeRelocate` calls to relocate the
> bars before the controls have been properly resized yet: The initial w/h values are set to the default (20 px / 100
> px), while the pref values are correctly set to 8 px.  This PR fixes that, by using the same prefWidth/prefHeight for
> both resizing and relocating.
> It has been tested on Mac OS and Linux (with `-Dcom.sun.javafx.touch=true`), and on Android and iOS.

Jose Pereda has updated the pull request incrementally with one additional commit since the last revision:

  Apply code formatting

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

Changes:
  - all: https://git.openjdk.java.net/jfx/pull/215/files
  - new: https://git.openjdk.java.net/jfx/pull/215/files/fcce06aa..fea9d186

Webrevs:
 - full: https://webrevs.openjdk.java.net/jfx/215/webrev.01
 - incr: https://webrevs.openjdk.java.net/jfx/215/webrev.00-01

  Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/jfx/pull/215.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/215/head:pull/215

PR: https://git.openjdk.java.net/jfx/pull/215