* gnu/packages/patches/ungoogled-chromium-system-jsoncpp.patch,
gnu/packages/patches/ungoogled-chromium-system-zlib.patch: Delete files.
* gnu/packages/patches/ungoogled-chromium-system-nspr.patch: New file.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.
* gnu/packages/chromium.scm (%preserved-third-party-files): Adjust for 84.
(%ungoogled-revision): Set to df199c04ff367da59ce52a23a3f3b305dd3b00c3.
(%debian-revision): Set to debian/83.0.4103.116-3.
(%gentoo-revision): Set to f3f649046d31ebdbc8c4a302b2384504eff78027.
(chromium-gcc-patchset, %chromium-gcc-patches): New variables.
(%gentoo-patches): Remove GCC patches, which have been moved to the above
repo. Add ffmpeg compatibility patch.
(%debian-patches): Add zlib and jsoncpp patch; remove nspr patch.
(%ungoogled-origin): Update hash.
(ungoogled-chromium-snippet): Add the new GCC patches. Remove obsolete local
patches, add new.
(xcb-proto/python2): New variable.
(ungoogled-chromium): Update to 84.0.4147.89-0..df199c0.
[arguments]: Add "is_unsafe_developer_build", "max_jobs_per_link",
"exclude_unwind_tables", "xcbproto_path", "perfetto_use_system_protobuf" to
#:configure-flags. Remove "linux_use_bundled_binutils". Adjust vulkan
header substitutions.
[native-inputs]: Remove YASM.
[inputs]: Change from FFMPEG-4.2 to FFMPEG. Add PROTOBUF and XCB-PROTO/PYTHON2.
