RFR: 8220484: JFXPanel renders a slanted image with a hidpi monitor scale of 125% or 175% [v4]

[Oliver Schmidtmer]

> In edge cases where monitor scaling of 1.25 or 1.75 is active, Math.ceil and Math.round produce different results and
> EmbeddedScene#getPixels in JFXPanel#paintComponent causes an off-by-one error on the line width and therefore sheared
> rendering.  The changes were already proposed by the submitter in JBS-8220484.
> 
> OCA is signed and send.

Oliver Schmidtmer has refreshed the contents of this pull request, and previous commits have been removed. The
incremental views will show differences compared to the previous content of the PR. The pull request contains two new
commits since the last revision:

 - Similar changes and test for FXCanvas
 - more solid test with shim and style independent color

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

Changes:
  - all: https://git.openjdk.java.net/jfx/pull/246/files
  - new: https://git.openjdk.java.net/jfx/pull/246/files/555c5f30..882f95c1

Webrevs:
 - full: https://webrevs.openjdk.java.net/jfx/246/webrev.03
 - incr: https://webrevs.openjdk.java.net/jfx/246/webrev.02-03

  Stats: 268 lines in 6 files changed: 130 ins; 0 del; 138 mod
  Patch: https://git.openjdk.java.net/jfx/pull/246.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/246/head:pull/246

PR: https://git.openjdk.java.net/jfx/pull/246