RFR: 8342565: [TestBug] StubTextLayout [v3]

[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 21 additional commits since the last revision:

 - review comments
 - Merge remote-tracking branch 'origin/master' into 8342565.stub.text.layout
 - atomic boolean
 - Merge branch 'master' into 8342565.stub.text.layout
 - cleanup
 - better test
 - cleanup
 - more magic
 - magic numbers
 - more
 - ... and 11 more: https://git.openjdk.org/jfx/compare/2598a462...b1042820

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/1667/files
  - new: https://git.openjdk.org/jfx/pull/1667/files/5010278f..b1042820

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1667&range=02
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1667&range=01-02

  Stats: 1671 lines in 27 files changed: 1265 ins; 318 del; 88 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