latest we have in portage: 20130411 version (two years ago) 20150126 available for download: https://github.com/google/closure-compiler/wiki/Binary-Downloads
should be all set now in the tree; thanks for the report! Commit message: Version bump http://sources.gentoo.org/dev-lang/closure-compiler-bin/closure-compiler-bin-20150126.ebuild?rev=1.1