RFR: 8276167: VirtualFlow.scrollToTop doesn't scroll to the top of the last element [v2]

[eduardsdv]

> Fix VirtualFlow.scrollToTop(int) doesn't scroll to the top of the last element but to the bottom of the last element.

eduardsdv 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 two additional commits since the last revision:

 - Merge branch 'openjdk:master' into bugfix/JDK-8276167-VirtualFlow-scrollToTop
 - JDK-8276167: fixing VirtualFlow.scrollToTop(int)

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

Changes:
  - all: https://git.openjdk.java.net/jfx/pull/656/files
  - new: https://git.openjdk.java.net/jfx/pull/656/files/087e11d3..a7820448

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jfx&pr=656&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jfx&pr=656&range=00-01

  Stats: 4192 lines in 92 files changed: 3532 ins; 274 del; 386 mod
  Patch: https://git.openjdk.java.net/jfx/pull/656.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/656/head:pull/656

PR: https://git.openjdk.java.net/jfx/pull/656