[Rev 02] RFR: 8237469: CssStyleHelper reuse check fixed

[Dean Wookey]

> Everything passes with the fix and 5 of the new tests fail without the fix.
> 
> removingThenAddingNodeToDifferentBranchGetsNewFontStyleTest
> movingBranchToDifferentBranchGetsNewCssVariableTest
> removingThenAddingNodeToDifferentBranchGetsCorrectInheritedValue
> removingThenAddingNodeToDifferentBranchGetsIneritableStyle
> movingNodeToDifferentBranchGetsNewFontStyleTest
> 
> I doubt this will cause a significant performance decrease. I think it's worth it for correctness. The only other thing is that I kept the fix to the minimum, but technically canReuseHelper now has a side effect. I could try rewrite some things if necessary, or maybe rename the method? Else leave it as is?
> 
> Originally introduced here: https://bugs.openjdk.java.net/browse/JDK-8090462/ https://github.com/openjdk/jfx/commit/834b0d05e7a2a8351403ec4a121eab312d80fd24#diff-9ec098280fa1aeed53c70243347e76ab

The pull request has been updated with 1 additional commit.

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

Added commits:
 - c7e60b9e: 8237469: Removed extra year in copyright header

Changes:
  - all: https://git.openjdk.java.net/jfx/pull/87/files
  - new: https://git.openjdk.java.net/jfx/pull/87/files/782f55e3..c7e60b9e

Webrevs:
 - full: https://webrevs.openjdk.java.net/jfx/87/webrev.02
 - incr: https://webrevs.openjdk.java.net/jfx/87/webrev.01-02

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jfx/pull/87.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/87/head:pull/87

PR: https://git.openjdk.java.net/jfx/pull/87