$ equery u chromium 
[ Legend : U - final flag setting for installation]
[        : I - package is installed with flag     ]
[ Colors : set, unset                             ]
 * Found these USE flags for www-client/chromium-71.0.3578.80:
 U I
 - - component-build    : Split build into more shared libraries to speed up linking. Mostly intended for debugging and development, NOT RECOMMENDED for general use.
 + + cups               : Add support for CUPS (Common Unix Printing System)
 - - custom-cflags      : Build with user-specified CFLAGS (unsupported)
 - - gnome-keyring      : Enable support for storing passwords via gnome-keyring
 + - hangouts           : Enable support for Google Hangouts features such as screen sharing
 + - jumbo-build        : Combine source files to speed up build process.
 - - kerberos           : Add kerberos support
 + - l10n_am            : Amharic
 + - l10n_ar            : Arabic
 + - l10n_bg            : Bulgarian
 + - l10n_bn            : Bengali
 + - l10n_ca            : Catalan
 + - l10n_cs            : Czech
 + - l10n_da            : Danish
 + - l10n_de            : German
 + - l10n_el            : Modern Greek
 + - l10n_en-GB         : English (United Kingdom)
 + - l10n_es            : Spanish
 + - l10n_es-419        : Spanish (Latin America)
 + - l10n_et            : Estonian
 + - l10n_fa            : Persian
 + - l10n_fi            : Finnish
 + - l10n_fil           : Filipino
 + - l10n_fr            : French
 + - l10n_gu            : Gujarati
 + - l10n_he            : Hebrew
 + - l10n_hi            : Hindi
 + - l10n_hr            : Croatian
 + - l10n_hu            : Hungarian
 + - l10n_id            : Indonesian
 + - l10n_it            : Italian
 + - l10n_ja            : Japanese
 + - l10n_kn            : Kannada
 + - l10n_ko            : Korean
 + - l10n_lt            : Lithuanian
 + - l10n_lv            : Latvian
 + - l10n_ml            : Malayalam
 + - l10n_mr            : Marathi
 + - l10n_ms            : Malay (macrolanguage)
 + - l10n_nb            : Norwegian Bokmål
 + - l10n_nl            : Dutch
 + - l10n_pl            : Polish
 + - l10n_pt-BR         : Portuguese (Brazil)
 + - l10n_pt-PT         : Portuguese (Portugal)
 + - l10n_ro            : Romanian
 + - l10n_ru            : Russian
 + - l10n_sk            : Slovak
 + - l10n_sl            : Slovenian
 + - l10n_sr            : Serbian
 + - l10n_sv            : Swedish
 + - l10n_sw            : Swahili (macrolanguage)
 + - l10n_ta            : Tamil
 + - l10n_te            : Telugu
 + - l10n_th            : Thai
 + - l10n_tr            : Turkish
 + - l10n_uk            : Ukrainian
 + - l10n_vi            : Vietnamese
 + - l10n_zh-CN         : Chinese (China)
 + - l10n_zh-TW         : Chinese (Taiwan)
 + - proprietary-codecs : Enable proprietary codecs like H.264, MP3
 - - pulseaudio         : Add support for PulseAudio sound server
 + - suid               : Build the SUID sandbox, which is only needed on CONFIG_USER_NS=n kernels
 - - system-ffmpeg      : Use system ffmpeg instead of the bundled one
 - - system-icu         : Use system icu instead of the bundled one
 - - system-libvpx      : Use system libvpx instead of the bundled one
 - - tcmalloc           : Use bundled tcmalloc instead of system malloc
 - - widevine           : Unsupported closed-source DRM capability (required by Netflix VOD)





$ cat /etc/portage/package.use/chromium 
www-client/chromium cups system-libvpx system-icu proprietary-codecs jumbo-build system-ffmpeg tcmalloc