RFR: 8189282: JavaFX: Invalid position of candidate pop-up of InputMethod in Hi-DPI on Windows [v5]

[Martin Fox]

> When reporting input method candidate position the code in GlassViewEventHandler is not applying the platform scale factors. This is causing incorrect IM positions to be reported to glass on hi-dpi monitors.
> 
> This PR a no-op on Mac since the platform scale factors are always 1.0. I don't think it affects the current Linux XIM code at all but XIM is so out-of-date it has become difficult to test. PR #1080 will replace the old XIM code and needs this fix to work properly on hi-dpi screens.

Martin Fox has updated the pull request incrementally with one additional commit since the last revision:

  Now handling stages that straddle two screens

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Changes:
  - all: https://git.openjdk.org/jfx/pull/1311/files
  - new: https://git.openjdk.org/jfx/pull/1311/files/3a599216..9198fc52

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1311&range=04
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1311&range=03-04

  Stats: 9 lines in 1 file changed: 3 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jfx/pull/1311.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1311/head:pull/1311

PR: https://git.openjdk.org/jfx/pull/1311