Fix sticky scroll height calculation for variable line heights#3748

utafrali wants to merge 2 commits intoeclipse-platform:mastereclipse-platform/eclipse.platform.ui:masterfrom

utafrali:fix/issue-3745-line-height-changes-when-emoji-is-added-utafrali/eclipse.platform.ui:fix/issue-3745-line-height-changes-when-emoji-is-added-Copy head branch name to clipboard