I suggest we just drop the inner border on Windows 7. The difference is pretty subtle and I think this is good enough for Windows 7 at this late point in its life.

Comment on attachment 8943003 [details] Bug 1430871 - Stop using -moz-border-*-colors for tree rows on Windows 7. https://reviewboard.mozilla.org/r/213276/#review219272 If box-shadow would work in treeitems it could be used as the second border but it seems it doesn't work. ::: toolkit/themes/windows/global/tree.css:505 (Diff revision 1) > } > } > + > + @media (-moz-os-version: windows-win7) { > + treechildren { > + --treechildren-selectedImage: linear-gradient(rgba(190,190,190,.1), rgba(190,190,190,.4)); Wouldn't it be better when this rules are in the common win7/win8 set and win8, which has less users, gets the redefintion rules? I don't know if this affects the speed, but then less users would be affected.

(In reply to Richard Marti (:Paenglab) from comment #2) > Comment on attachment 8943003 [details] > Bug 1430871 - Stop using -moz-border-*-colors for tree rows on Windows 7. > > https://reviewboard.mozilla.org/r/213276/#review219272 > > If box-shadow would work in treeitems it could be used as the second border > but it seems it doesn't work. > > ::: toolkit/themes/windows/global/tree.css:505 > (Diff revision 1) > > } > > } > > + > > + @media (-moz-os-version: windows-win7) { > > + treechildren { > > + --treechildren-selectedImage: linear-gradient(rgba(190,190,190,.1), rgba(190,190,190,.4)); > > Wouldn't it be better when this rules are in the common win7/win8 set and > win8, which has less users, gets the redefintion rules? I don't know if this > affects the speed, but then less users would be affected. Presumably we'll drop Win7 support before dropping Win8 support. When this happens, the way I wrote the rules will make it easier to remove the Win7 stuff.

Pushed by dgottwald@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/02100721e427 Stop using -moz-border-*-colors for tree rows on Windows 7. r=Paenglab