Bug 1035337 - Introduce API to record when the infobar is hidden due to "Never translate this language/site". r=felipe

--HG--
extra : rebase_source : 04dd1e060efad6160997194ba1b128c7f8a5db36
extra : histedit_source : be5f46896497e1bef1aa5ace5850793c4556527d
Bug 1035337 - Record when the infobar is hidden due to "Never translate this language/site". r=felipe

--HG--
extra : rebase_source : ceb8cf7df82555eef2d073e41f6af8888643c659
extra : histedit_source : 478dc6afdbb7697e93cc44f7d3a716c6347b6c0c