RFR: 8289587: IllegalArgumentException: Color.rgb's red parameter (-16776961) expects color values 0-255 [v2]

[Jose Pereda]

> This PR solves an IAE exception that happens when invoking a ColorChooser control within a WebView, by getting the r, g, b values from the Color before calling the colorChooser.
> 
> A system test is included, to verify that there is no exception and the two native functions that are modified produce the expected color components.

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

  Rework test

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Changes:
  - all: https://git.openjdk.org/jfx/pull/809/files
  - new: https://git.openjdk.org/jfx/pull/809/files/456d3ce8..c94e695e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=809&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=809&range=00-01

  Stats: 150 lines in 1 file changed: 47 ins; 51 del; 52 mod
  Patch: https://git.openjdk.org/jfx/pull/809.diff
  Fetch: git fetch https://git.openjdk.org/jfx pull/809/head:pull/809

PR: https://git.openjdk.org/jfx/pull/809