/usr/lib/chromium-browser/chrome: error while loading shared libraries: libssl3.so.12: cannot open shared object file: No such file or directory chromium-bin workarounds this by doing symlinks into ${CHROMIUM_HOME}/lib/
Created attachment 205044 [details] emerge --info output
This is most probably caused by a dev-libs/nss upgrade: if you upgraded it to a version >=3.12.4 after emerging chromium, you will need to remerge chromium, as the new nss versions have reverted back to using upstream soname (mentioned in nss postinstall message). chromium is one of the affected packages (and this is not spotted by revdep-rebuild, as the file name did not change).
yes, that was the case remerging chromium fixed