RFR: 8342565: [TestBug] StubTextLayout [v2]

[Andy Goryachev]

> Changed the StubTextLayout to use product PrismTextLayout with much simplified glyph layout (via stubbed fonts).  The new layout assumes all the glyphs are squares of font size, while the bold type face produces wider glyphs (by 1 pixel).  The default font size has changed from 10 to 12 to make it closer to win/linux.
> 
> This brings the test environment closer to the product configuration and expands the capabilities of our headless testing pipeline, which will be useful for upcoming behavior tests.
> 
> Existing tests have been adjusted/reworked mainly due to default font size change.

Andy Goryachev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 19 additional commits since the last revision:

 - atomic boolean
 - Merge branch 'master' into 8342565.stub.text.layout
 - cleanup
 - better test
 - cleanup
 - more magic
 - magic numbers
 - more
 - add exports
 - stub fonts
 - ... and 9 more: https://git.openjdk.org/jfx/compare/f8bcfa32...5010278f

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/1667/files
  - new: https://git.openjdk.org/jfx/pull/1667/files/a4a3ebb3..5010278f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1667&range=01
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1667&range=00-01

  Stats: 291 lines in 12 files changed: 186 ins; 79 del; 26 mod
  Patch: https://git.openjdk.org/jfx/pull/1667.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1667/head:pull/1667

PR: https://git.openjdk.org/jfx/pull/1667