diff --git a/gnu/local.mk b/gnu/local.mk
index 154b03313a..1496bae066 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -100,6 +100,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/packages/check.scm			\
   %D%/packages/chemistry.scm			\
   %D%/packages/chez.scm				\
+  %D%/packages/chromium.scm			\
   %D%/packages/ci.scm				\
   %D%/packages/cinnamon.scm			\
   %D%/packages/clojure.scm			\
diff --git a/gnu/packages/aux-files/chromium/master-preferences.json b/gnu/packages/aux-files/chromium/master-preferences.json
new file mode 100644
index 0000000000..5a2049fa72
--- /dev/null
+++ b/gnu/packages/aux-files/chromium/master-preferences.json
@@ -0,0 +1,26 @@
+{
+    "distribution": {
+        "import_bookmarks": false,
+        "make_chrome_default": false,
+        "make_chrome_default_for_user": false,
+        "verbose_logging": true,
+        "skip_first_run_ui": true,
+        "suppress_first_run_default_browser_prompt": true
+    },
+    "browser": {
+        "has_seen_welcome_page" : true,
+        "check_default_browser" : false
+    },
+    "dns_prefetching": {
+        "enabled": false
+    },
+    "alternate_error_pages": {
+        "enabled": false
+    },
+    "hardware": {
+        "audio_capture_enabled": false
+    },
+    "default_apps": "noinstall",
+    "hide_web_store_icon": true,
+    "homepage": "https://www.gnu.org/software/guix/"
+}
diff --git a/gnu/packages/chromium.scm b/gnu/packages/chromium.scm
new file mode 100644
index 0000000000..85e96131e3
--- /dev/null
+++ b/gnu/packages/chromium.scm
@@ -0,0 +1,726 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2019 Marius Bakke <mbakke@fastmail.com>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu packages chromium)
+  #:use-module ((guix licenses) #:prefix license:)
+  #:use-module (guix packages)
+  #:use-module (guix gexp)
+  #:use-module (guix store)
+  #:use-module (guix monads)
+  #:use-module (guix download)
+  #:use-module (guix git-download)
+  #:use-module (guix utils)
+  #:use-module (guix build-system gnu)
+  #:use-module (gnu packages)
+  #:use-module (gnu packages assembly)
+  #:use-module (gnu packages base)
+  #:use-module (gnu packages bison)
+  #:use-module (gnu packages build-tools)
+  #:use-module (gnu packages compression)
+  #:use-module (gnu packages cups)
+  #:use-module (gnu packages curl)
+  #:use-module (gnu packages fontutils)
+  #:use-module (gnu packages gcc)
+  #:use-module (gnu packages ghostscript)
+  #:use-module (gnu packages gl)
+  #:use-module (gnu packages glib)
+  #:use-module (gnu packages gnome)
+  #:use-module (gnu packages gnuzilla)
+  #:use-module (gnu packages gperf)
+  #:use-module (gnu packages gtk)
+  #:use-module (gnu packages icu4c)
+  #:use-module (gnu packages image)
+  #:use-module (gnu packages libevent)
+  #:use-module (gnu packages libffi)
+  #:use-module (gnu packages linux)
+  #:use-module (gnu packages kerberos)
+  #:use-module (gnu packages ninja)
+  #:use-module (gnu packages node)
+  #:use-module (gnu packages pciutils)
+  #:use-module (gnu packages pkg-config)
+  #:use-module (gnu packages pulseaudio)
+  #:use-module (gnu packages python)
+  #:use-module (gnu packages python-web)
+  #:use-module (gnu packages python-xyz)
+  #:use-module (gnu packages regex)
+  #:use-module (gnu packages serialization)
+  #:use-module (gnu packages speech)
+  #:use-module (gnu packages tls)
+  #:use-module (gnu packages valgrind)
+  #:use-module (gnu packages vulkan)
+  #:use-module (gnu packages video)
+  #:use-module (gnu packages xiph)
+  #:use-module (gnu packages xml)
+  #:use-module (gnu packages xdisorg)
+  #:use-module (gnu packages xorg))
+
+(define %preserved-third-party-files
+  '("base/third_party/dmg_fp" ;X11-style
+    "base/third_party/dynamic_annotations" ;BSD-2
+    "base/third_party/icu" ;Unicode, X11-style
+    "base/third_party/superfasthash" ;BSD-3
+    "base/third_party/symbolize" ;BSD-3
+    "base/third_party/xdg_mime" ;LGPL2.1+ or Academic 2.0
+    "base/third_party/xdg_user_dirs" ;Expat
+    "chrome/third_party/mozilla_security_manager" ;MPL-1.1/GPL2+/LGPL2.1+
+    "courgette/third_party/bsdiff" ;BSD-2, BSD protection license
+    "courgette/third_party/divsufsort" ;Expat
+    "net/third_party/http2" ;BSD-3
+    "net/third_party/mozilla_security_manager" ;MPL-1.1/GPL2+/LGPL2.1+
+    "net/third_party/nss" ;MPL-2.0
+    "net/third_party/quic" ;BSD-3
+    "net/third_party/spdy" ;BSD-3
+    "net/third_party/uri_template" ;ASL2.0
+    "third_party/abseil-cpp" ;ASL2.0
+    "third_party/adobe/flash/flapper_version.h" ;no license, trivial
+    "third_party/angle" ;BSD-3
+    "third_party/angle/src/common/third_party/base" ;BSD-3
+    "third_party/angle/src/common/third_party/smhasher" ;Public domain
+    "third_party/angle/src/common/third_party/xxhash" ;BSD-2
+    "third_party/angle/src/third_party/compiler" ;BSD-2
+    "third_party/angle/src/third_party/libXNVCtrl" ;Expat
+    "third_party/angle/src/third_party/trace_event" ;BSD-3
+    "third_party/angle/third_party/glslang" ;BSD-3
+    "third_party/angle/third_party/spirv-headers" ;Expat
+    "third_party/angle/third_party/spirv-tools" ;Expat
+    "third_party/angle/third_party/vulkan-headers" ;ASL2.0
+    "third_party/angle/third_party/vulkan-loader" ;ASL2.0
+    "third_party/angle/third_party/vulkan-tools" ;ASL2.0
+    "third_party/angle/third_party/vulkan-validation-layers" ;ASL2.0
+    "third_party/apple_apsl" ;APSL2.0
+    "third_party/blink" ;BSD-3
+    "third_party/boringssl" ;OpenSSL/ISC (Google additions are ISC)
+    "third_party/boringssl/src/third_party/fiat" ;Expat
+    "third_party/breakpad" ;BSD-3
+    "third_party/brotli" ;Expat
+    "third_party/cacheinvalidation" ;ASL2.0
+    "third_party/catapult" ;BSD-3
+    "third_party/catapult/common/py_vulcanize/third_party/rcssmin" ;ASL2.0
+    "third_party/catapult/common/py_vulcanize/third_party/rjsmin" ;ASL2.0
+    "third_party/catapult/third_party/polymer" ;BSD-3
+    "third_party/catapult/tracing/third_party/d3" ;BSD-3
+    "third_party/catapult/tracing/third_party/gl-matrix" ;Expat
+    "third_party/catapult/tracing/third_party/jszip" ;Expat or GPL3
+    "third_party/catapult/tracing/third_party/mannwhitneyu" ;Expat
+    "third_party/catapult/tracing/third_party/oboe" ;BSD-2
+    "third_party/catapult/tracing/third_party/pako" ;Expat
+    "third_party/ced" ;BSD-3
+    "third_party/cld_3" ;ASL2.0
+    "third_party/crashpad" ;ASL2.0
+    "third_party/crashpad/crashpad/third_party/zlib/zlib_crashpad.h" ;Zlib
+    "third_party/crc32c" ;BSD-3
+    "third_party/cros_system_api" ;BSD-3
+    "third_party/dom_distiller_js" ;BSD-3
+    "third_party/fips181" ;BSD-3
+    "third_party/flatbuffers" ;ASL2.0
+    "third_party/google_input_tools" ;ASL2.0
+    "third_party/google_input_tools/third_party/closure_library" ;ASL2.0
+    "third_party/google_input_tools/third_party/closure_library/third_party/closure" ;Expat
+    "third_party/googletest" ;BSD-3
+    "third_party/hunspell" ;MPL1.1/GPL2+/LGPL2.1+
+    "third_party/iccjpeg" ;IJG
+    "third_party/inspector_protocol" ;BSD-3
+    "third_party/jinja2" ;BSD-3
+    "third_party/jstemplate" ;ASL2.0
+    "third_party/khronos" ;Expat, SGI
+    "third_party/leveldatabase" ;BSD-3
+    "third_party/libXNVCtrl" ;Expat
+    "third_party/libaddressinput" ;ASL2.0
+    "third_party/libaom" ;BSD-2 or "Alliance for Open Media Patent License 1.0"
+    "third_party/libaom/source/libaom/third_party/vector" ;Expat
+    "third_party/libaom/source/libaom/third_party/x86inc" ;ISC
+    "third_party/libjingle_xmpp" ;BSD-3
+    "third_party/libphonenumber" ;ASL2.0
+    "third_party/libsecret" ;LGPL2.1+
+    "third_party/libsrtp" ;BSD-3
+    "third_party/libsync" ;ASL2.0
+    "third_party/libudev" ;LGPL2.1+
+    "third_party/libwebm" ;BSD-3
+    "third_party/libxml/chromium" ;BSD-3
+    "third_party/libyuv" ;BSD-3
+    "third_party/lss" ;BSD-3
+    "third_party/markupsafe" ;BSD-3
+    "third_party/mesa_headers" ;Expat, SGI
+    "third_party/metrics_proto" ;BSD-3
+    "third_party/modp_b64" ;BSD-3
+    "third_party/nasm" ;BSD-2
+    "third_party/node" ;Expat
+    "third_party/node/node_modules/polymer-bundler/lib/third_party/UglifyJS2" ;BSD-2
+    "third_party/ots" ;BSD-3
+    "third_party/pdfium" ;BSD-3
+    "third_party/pdfium/third_party/agg23" ;Expat
+    "third_party/pdfium/third_party/base" ;BSD-3
+    "third_party/pdfium/third_party/bigint" ;Public domain, BSD-3
+    "third_party/pdfium/third_party/skia_shared" ;BSD-3
+    "third_party/pdfium/third_party/freetype/include/pstables.h" ;FreeType
+    "third_party/ply" ;BSD-3
+    "third_party/polymer" ;BSD-3
+    "third_party/protobuf" ;BSD-3
+    "third_party/protobuf/third_party/six" ;Expat
+    "third_party/pyjson5" ;ASL2.0
+    "third_party/qcms" ;Expat
+    "third_party/rnnoise" ;BSD-3
+    "third_party/s2cellid" ;ASL2.0
+    "third_party/sfntly" ;ASL2.0
+    "third_party/skia" ;BSD-3
+    "third_party/skia/third_party/gif" ;MPL1.1/GPL2+/LGPL2.1+
+    "third_party/skia/third_party/skcms" ;BSD-3
+    "third_party/skia/third_party/vulkan" ;BSD-3
+    "third_party/smhasher" ;Expat, public domain
+    "third_party/speech-dispatcher" ;GPL2+
+    "third_party/spirv-headers" ;ASL2.0
+    "third_party/SPIRV-Tools" ;ASL2.0
+    "third_party/sqlite" ;Public domain
+    "third_party/ungoogled" ;BSD-3
+    "third_party/usb_ids" ;BSD-3
+    "third_party/usrsctp" ;BSD-2
+    "third_party/web-animations-js" ;ASL2.0
+    "third_party/webdriver" ;ASL2.0
+    "third_party/webrtc" ;BSD-3
+    "third_party/webrtc/common_audio/third_party/fft4g" ;Non-copyleft
+    "third_party/webrtc/common_audio/third_party/spl_sqrt_floor" ;Public domain
+    "third_party/webrtc/modules/third_party/fft" ;Non-copyleft
+    "third_party/webrtc/modules/third_party/g711" ;Public domain
+    "third_party/webrtc/modules/third_party/g722" ;Public domain
+    "third_party/webrtc/rtc_base/third_party/base64" ;Non-copyleft
+    "third_party/webrtc/rtc_base/third_party/sigslot" ;Public domain
+    "third_party/widevine/cdm/widevine_cdm_version.h" ;BSD-3
+    "third_party/widevine/cdm/widevine_cdm_common.h" ;BSD-3
+    "third_party/woff2" ;ASL2.0
+    "third_party/xdg-utils" ;Expat
+    "third_party/yasm/run_yasm.py" ;BSD-2 or BSD-3
+    "third_party/zlib/google" ;BSD-3
+    "url/third_party/mozilla" ;BSD-3, MPL1.1/GPL2+/LGPL2.1+
+    "v8/src/third_party/utf8-decoder" ;Expat
+    "v8/src/third_party/valgrind" ;BSD-4
+    "v8/third_party/inspector_protocol" ;BSD-3
+    "v8/third_party/v8/builtins")) ;PSFL
+
+(define* (computed-origin-method gexp-promise hash-algo hash
+                                 #:optional (name "source")
+                                 #:key (system (%current-system))
+                                 (guile (default-guile)))
+  "Return a derivation that executes the G-expression that results
+from forcing GEXP-PROMISE."
+  (mlet %store-monad ((guile (package->derivation guile system)))
+    (gexp->derivation (or name "computed-origin")
+                      (force gexp-promise)
+                      #:system system
+                      #:guile-for-build guile)))
+
+(define %chromium-version "72.0.3626.96")
+(define %ungoogled-revision "82b1194615a6542c28edfc5505d357c9dfca88c7")
+
+;; This is a "computed" origin that does the following:
+;; 1) Runs the Ungoogled scripts on a pristine Chromium tarball.
+;; 2) Prunes all third_party folders that are not explicitly preserved.
+;; 3) Adjusts "GN" build files such that system libraries are preferred.
+(define ungoogled-chromium-source
+  (let* ((chromium-source
+          (origin
+            (method url-fetch)
+            (uri (string-append "https://commondatastorage.googleapis.com"
+                                "/chromium-browser-official/chromium-"
+                                %chromium-version ".tar.xz"))
+            (sha256
+             (base32
+              "0fxavi4nwfiyb15lqm02vlq6kb8i4ipxnd7hp45bm7jdmhmgbnmj"))))
+         (ungoogled-source
+          (origin
+            (method git-fetch)
+            (uri (git-reference (url "https://github.com/Eloston/ungoogled-chromium")
+                                (commit %ungoogled-revision)))
+            (file-name (git-file-name "ungoogled-chromium"
+                                      (string-take %ungoogled-revision 7)))
+            (sha256
+             (base32
+              "067bccrv67wh8p0vak0n38gc8mvb9hvx2pz83r0y1iiqkhrglnp3")))))
+
+    (origin
+      (method computed-origin-method)
+      (file-name (string-append "ungoogled-chromium-" %chromium-version ".tar.xz"))
+      (sha256 #f)
+      (uri
+       (delay
+         (with-imported-modules '((guix build utils))
+           #~(begin
+               (use-modules (guix build utils))
+               (let ((chromium-dir    (string-append "chromium-" #$%chromium-version))
+                     (preserved-files (list #$@%preserved-third-party-files)))
+
+                 (mkdir "/tmp/bin")
+                 (set-path-environment-variable
+                  "PATH" '("bin")
+                  (list "/tmp"
+                        #+(canonical-package patch)
+                        #+(canonical-package xz)
+                        #+(canonical-package tar)
+                        #+python-2
+                        #+python))
+
+                 (copy-recursively #+ungoogled-source "/tmp/ungoogled")
+
+                 (with-directory-excursion "/tmp/ungoogled"
+
+                   ;; Create a custom "bundle" that inherits from linux_rooted
+                   ;; and adds an additional patch.
+                   (format #t "Creating Guix config bundle...~%")
+                   (force-output)
+                   (mkdir-p "config_bundles/guix")
+                   (call-with-output-file "config_bundles/guix/bundlemeta.ini"
+                     (lambda (port)
+                       (format port
+                               "[bundle]
+display_name = GNU Guix
+depends = linux_rooted\n")))
+                   (call-with-output-file "config_bundles/guix/patch_order.list"
+                     (lambda (port)
+                       (format port "debian_buster/system/openjpeg.patch\n")))
+
+                   (format #t "Unpacking chromium tarball...~%")
+                   (force-output)
+                   (invoke "tar" "xf" #+chromium-source)
+
+                   (format #t "Ungooglifying...~%")
+                   (force-output)
+                   (invoke "python3" "run_buildkit_cli.py" "prune"
+                           "-b" "config_bundles/guix" chromium-dir)
+                   (invoke "python3" "run_buildkit_cli.py" "patches" "apply"
+                           "-b" "config_bundles/guix" chromium-dir)
+                   (invoke "python3" "run_buildkit_cli.py" "domains" "apply"
+                           "-b" "config_bundles/linux_rooted"
+                           "-c" "/tmp/domainscache.tar.gz" chromium-dir)
+
+                   (with-directory-excursion chromium-dir
+                     (format #t "Pruning third party files...~%")
+                     (force-output)
+                     (apply invoke "python"
+                             "build/linux/unbundle/remove_bundled_libraries.py"
+                             "--do-remove" preserved-files)
+
+                     (format #t "Replacing GN files...~%")
+                     (force-output)
+                     (invoke "python3" "build/linux/unbundle/replace_gn_files.py"
+                             "--system-libraries" "ffmpeg" "flac" "fontconfig"
+                             "freetype" "harfbuzz-ng" "icu" "libdrm" "libevent"
+                             "libjpeg" "libpng" "libvpx" "libwebp" "libxml"
+                             "libxslt" "openh264" "opus" "re2" "snappy" "yasm"
+                             "zlib"))
+
+                   (format #t (string-append "Packing new Ungoogled tarball ...~%"))
+                   (force-output)
+                   (invoke "tar" "cvfa" #$output
+                           ;; Avoid non-determinism in the archive.
+                           "--mtime=@0"
+                           "--owner=root:0"
+                           "--group=root:0"
+                           "--sort=name"
+                           chromium-dir)
+
+                   #t)))))))))
+
+(define opus+custom
+  (package/inherit opus
+    (name "opus+custom")
+    (arguments
+     (substitute-keyword-arguments (package-arguments opus)
+       ((#:configure-flags flags ''())
+        ;; Opus Custom is an optional extension of the Opus
+        ;; specification that allows for unsupported frame
+        ;; sizes.  Chromium requires that this is enabled.
+        `(cons "--enable-custom-modes"
+               ,flags))))))
+
+(define-public ungoogled-chromium
+  (package
+    (name "ungoogled-chromium")
+    (version %chromium-version)
+    (synopsis "Graphical web browser")
+    (source ungoogled-chromium-source)
+    (build-system gnu-build-system)
+    (arguments
+     `(#:tests? #f
+       ;; FIXME: There is a "gn" option specifically for setting -rpath, but
+       ;; it overrides the RUNPATH set by the linker.
+       #:validate-runpath? #f
+       #:modules ((guix build gnu-build-system)
+                  (guix build utils)
+                  (ice-9 ftw)
+                  (ice-9 regex)
+                  (srfi srfi-26))
+       #:configure-flags
+       ;; See tools/gn/docs/cookbook.md and
+       ;; https://www.chromium.org/developers/gn-build-configuration
+       ;; for usage.  Run "./gn args . --list" in the Release
+       ;; directory for an exhaustive list of supported flags.
+       ;; (Note: The 'configure' phase will do that for you.)
+       (list "is_debug=false"
+             "use_gold=false"
+             "use_lld=false"
+             "linux_use_bundled_binutils=false"
+             "use_custom_libcxx=false"
+             "use_sysroot=false"
+             "enable_precompiled_headers=false"
+             "goma_dir=\"\""
+             "enable_nacl=false"
+             "enable_nacl_nonsfi=false"
+             "use_allocator=\"none\""   ;don't use tcmalloc
+             "use_unofficial_version_number=false"
+
+             ;; Define a custom toolchain that simply looks up CC, AR and
+             ;; friends from the environment.
+             "custom_toolchain=\"//build/toolchain/linux/unbundle:default\""
+             "host_toolchain=\"//build/toolchain/linux/unbundle:default\""
+
+             ;; Don't assume it's clang.
+             "is_clang=false"
+
+             ;; Optimize for building everything at once, as opposed to
+             ;; incrementally for development.  See "docs/jumbo.md".
+             "use_jumbo_build=true"
+
+             ;; Disable type-checking for the Web UI to avoid a Java dependency.
+             "closure_compile=false"
+
+             ;; Disable debugging features to save space.
+             "blink_symbol_level=0"
+             "enable_iterator_debugging=false"
+
+             ;; Some of the unbundled libraries throws deprecation
+             ;; warnings, etc.  Ignore it.
+             "treat_warnings_as_errors=false"
+
+             ;; Don't add any API keys.  End users can set them in the
+             ;; environment if desired.  See
+             ;; <https://www.chromium.org/developers/how-tos/api-keys>.
+             "use_official_google_api_keys=false"
+
+             ;; Disable "safe browsing", which pulls in a dependency on
+             ;; the nonfree "unrar" program (as of m66).
+             "safe_browsing_mode=0"
+
+             ;; Disable "field trials".
+             "fieldtrial_testing_like_official_build=true"
+
+             ;; Ungoogled components.
+             "enable_mdns=false"
+             "enable_one_click_signin=false"
+             "enable_reading_list=false"
+             "enable_remoting=false"
+             "enable_reporting=false"
+             "enable_service_discovery=false"
+             "enable_swiftshader=false"
+             "use_vaapi=true"
+
+             ;; Use system libraries where possible.
+             "use_system_freetype=true"
+             "use_system_harfbuzz=true"
+             "use_system_lcms2=true"
+             "use_system_libdrm=true"
+             "use_system_libjpeg=true"
+             "use_system_libpng=true"
+             ;;"use_system_libsync=true"
+             "use_system_zlib=true"
+
+             "use_gnome_keyring=false"  ;deprecated by libsecret
+             "use_openh264=true"
+             "use_pulseaudio=true"
+             "link_pulseaudio=true"
+
+             ;; Don't arbitrarily restrict formats supported by system ffmpeg.
+             "proprietary_codecs=true"
+             "ffmpeg_branding=\"Chrome\""
+
+             ;; WebRTC stuff.
+             "rtc_use_h264=true"
+             ;; Don't use bundled sources.
+             "rtc_build_json=false"
+             "rtc_build_libevent=false"
+             "rtc_build_libvpx=false"
+             "rtc_build_opus=false"
+             "rtc_build_ssl=false"
+
+             "rtc_build_libsrtp=true"   ;FIXME: fails to find headers
+             "rtc_build_usrsctp=true"   ;TODO: package this
+             (string-append "rtc_jsoncpp_root=\""
+                            (assoc-ref %build-inputs "jsoncpp")
+                            "/include/jsoncpp/json\"")
+             (string-append "rtc_ssl_root=\""
+                            (assoc-ref %build-inputs "openssl")
+                            "/include/openssl\""))
+       #:phases
+       (modify-phases %standard-phases
+         (add-after 'unpack 'patch-stuff
+           (lambda* (#:key inputs #:allow-other-keys)
+             (substitute* "printing/cups_config_helper.py"
+               (("cups_config =.*")
+                (string-append "cups_config = '" (assoc-ref inputs "cups")
+                               "/bin/cups-config'\n")))
+
+             (substitute*
+                 '("base/process/launch_posix.cc"
+                   "base/third_party/dynamic_annotations/dynamic_annotations.c"
+                   "sandbox/linux/seccomp-bpf/sandbox_bpf.cc"
+                   "sandbox/linux/services/credentials.cc"
+                   "sandbox/linux/services/namespace_utils.cc"
+                   "sandbox/linux/services/syscall_wrappers.cc"
+                   "sandbox/linux/syscall_broker/broker_host.cc")
+               (("include \"base/third_party/valgrind/") "include \"valgrind/"))
+
+             (for-each (lambda (file)
+                         (substitute* file
+                           ;; Fix opus include path.
+                           ;; Do not substitute opus_private.h.
+                           (("#include \"opus\\.h\"")
+                            "#include \"opus/opus.h\"")
+                           (("#include \"opus_custom\\.h\"")
+                            "#include \"opus/opus_custom.h\"")
+                           (("#include \"opus_defines\\.h\"")
+                            "#include \"opus/opus_defines.h\"")
+                           (("#include \"opus_multistream\\.h\"")
+                            "#include \"opus/opus_multistream.h\"")
+                           (("#include \"opus_types\\.h\"")
+                            "#include \"opus/opus_types.h\"")))
+                       (find-files (string-append "third_party/webrtc/modules"
+                                                  "/audio_coding/codecs/opus")))
+
+             (substitute* "chrome/common/chrome_paths.cc"
+               (("/usr/share/chromium/extensions")
+                ;; TODO: Add ~/.guix-profile.
+                "/run/current-system/profile/share/chromium/extensions"))
+
+             ;; XXX: Should be unnecessary when use_system_lcms2=true.
+             (substitute* "third_party/pdfium/core/fxcodec/codec/ccodec_iccmodule.h"
+               (("include \"third_party/lcms/include/lcms2\\.h\"")
+                "include \"lcms2.h\""))
+
+             (substitute*
+                 "third_party/breakpad/breakpad/src/common/linux/libcurl_wrapper.h"
+               (("include \"third_party/curl") "include \"curl"))
+
+             (substitute* "third_party/webrtc/rtc_base/strings/json.h"
+               (("#include \"third_party/jsoncpp/") "#include \"json/"))
+
+             (substitute* "media/base/decode_capabilities.cc"
+               (("third_party/libvpx/source/libvpx/") ""))
+
+             (substitute* "ui/gfx/skia_util.h"
+               (("third_party/vulkan/include/") ""))
+
+             ;; Building chromedriver embeds some files using the ZIP
+             ;; format which doesn't support timestamps before
+             ;; 1980. Therefore, advance the timestamps of the files
+             ;; which are included so that building chromedriver
+             ;; works.
+             (let ((circa-1980 (* 10 366 24 60 60)))
+               (for-each (lambda (file)
+                           (utime file circa-1980 circa-1980))
+                         '("chrome/test/chromedriver/extension/background.js"
+                           "chrome/test/chromedriver/extension/manifest.json")))
+
+             #t))
+         (add-before 'configure 'prepare-build-environment
+           (lambda* (#:key inputs #:allow-other-keys)
+
+             ;; Make sure the right build tools are used.
+             (setenv "AR" "ar") (setenv "NM" "nm")
+             (setenv "CC" "gcc") (setenv "CXX" "g++")
+
+             ;; Work around <https://bugs.gnu.org/30756>.
+             (unsetenv "C_INCLUDE_PATH")
+             (unsetenv "CPLUS_INCLUDE_PATH")
+
+             ;; TODO: pre-compile instead. Avoids a race condition.
+             (setenv "PYTHONDONTWRITEBYTECODE" "1")
+
+             ;; XXX: How portable is this.
+             (mkdir-p "third_party/node/linux/node-linux-x64")
+             (symlink (string-append (assoc-ref inputs "node") "/bin")
+                      "third_party/node/linux/node-linux-x64/bin")
+
+             #t))
+         (replace 'configure
+           (lambda* (#:key configure-flags #:allow-other-keys)
+             (let ((args (string-join configure-flags " ")))
+               ;; Generate ninja build files.
+               (invoke "gn" "gen" "out/Release"
+                       (string-append "--args=" args))
+
+               ;; Print the full list of supported arguments as well as
+               ;; their current status for convenience.
+               (format #t "Dumping configure flags...\n")
+               (invoke "gn" "args" "out/Release" "--list"))))
+         (replace 'build
+           (lambda* (#:key outputs #:allow-other-keys)
+             (invoke "ninja" "-C" "out/Release"
+                     "-j" (number->string (parallel-job-count))
+                     "chrome"
+                     "chromedriver")))
+         (replace 'install
+           (lambda* (#:key inputs outputs #:allow-other-keys)
+             (let* ((out            (assoc-ref outputs "out"))
+                    (bin            (string-append out "/bin"))
+                    (exe            (string-append bin "/chromium"))
+                    (lib            (string-append out "/lib"))
+                    (man            (string-append out "/share/man/man1"))
+                    (applications   (string-append out "/share/applications"))
+                    (install-regexp (make-regexp "\\.(bin|pak)$"))
+                    (locales        (string-append lib "/locales"))
+                    (resources      (string-append lib "/resources"))
+                    (preferences    (assoc-ref inputs "master-preferences"))
+                    (gtk+           (assoc-ref inputs "gtk+"))
+                    (mesa           (assoc-ref inputs "mesa"))
+                    (nss            (assoc-ref inputs "nss"))
+                    (udev           (assoc-ref inputs "udev"))
+                    (sh             (which "sh")))
+
+               (substitute* '("chrome/app/resources/manpage.1.in"
+                              "chrome/installer/linux/common/desktop.template")
+                 (("@@MENUNAME@@") "Chromium")
+                 (("@@PACKAGE@@") "chromium")
+                 (("/usr/bin/@@USR_BIN_SYMLINK_NAME@@") exe))
+
+               (mkdir-p man)
+               (copy-file "chrome/app/resources/manpage.1.in"
+                          (string-append man "/chromium.1"))
+
+               (mkdir-p applications)
+               (copy-file "chrome/installer/linux/common/desktop.template"
+                          (string-append applications "/chromium.desktop"))
+
+               (mkdir-p lib)
+               (copy-file preferences (string-append lib "/master_preferences"))
+
+               (with-directory-excursion "out/Release"
+                 (for-each (lambda (file)
+                             (install-file file lib))
+                           (scandir "." (cut regexp-exec install-regexp <>)))
+                 (copy-file "chrome" (string-append lib "/chromium"))
+
+                 ;; TODO: Install icons from "../../chrome/app/themes" into
+                 ;; "out/share/icons/hicolor/$size".
+                 (install-file
+                  "product_logo_48.png"
+                  (string-append out "/share/icons/48x48/chromium.png"))
+
+                 (copy-recursively "locales" locales)
+                 (copy-recursively "resources" resources)
+
+                 (mkdir-p bin)
+                 (symlink "../lib/chromium" exe)
+                 (install-file "chromedriver" bin)
+
+                 (wrap-program exe
+                   ;; TODO: Get these in RUNPATH.
+                   `("LD_LIBRARY_PATH" ":" prefix
+                     (,(string-append lib ":" nss "/lib/nss:" gtk+ "/lib:"
+                                      mesa "/lib:" udev "/lib")))
+                   ;; Avoid file manager crash.  See <https://bugs.gnu.org/26593>.
+                   `("XDG_DATA_DIRS" ":" prefix (,(string-append gtk+ "/share"))))
+                 #t)))))))
+    (native-inputs
+     `(("bison" ,bison)
+       ("gcc" ,gcc-8)
+       ("gn" ,gn)
+       ("gperf" ,gperf)
+       ("ninja" ,ninja)
+       ("node" ,node)
+       ("pkg-config" ,pkg-config)
+       ("which" ,which)
+       ("yasm" ,yasm)
+
+       ;; This file contains defaults for new user profiles.
+       ("master-preferences" ,(local-file "aux-files/chromium/master-preferences.json"))
+
+       ("python-beautifulsoup4" ,python2-beautifulsoup4)
+       ("python-html5lib" ,python2-html5lib)
+       ("python" ,python-2)))
+    (inputs
+     `(("alsa-lib" ,alsa-lib)
+       ("atk" ,atk)
+       ("cups" ,cups)
+       ("curl" ,curl)
+       ("dbus" ,dbus)
+       ("dbus-glib" ,dbus-glib)
+       ("expat" ,expat)
+       ("flac" ,flac)
+       ("ffmpeg" ,ffmpeg)
+       ("fontconfig" ,fontconfig)
+       ("freetype" ,freetype)
+       ("gdk-pixbuf" ,gdk-pixbuf)
+       ("glib" ,glib)
+       ("gtk+" ,gtk+)
+       ("harfbuzz" ,harfbuzz)
+       ("icu4c" ,icu4c)
+       ("jsoncpp" ,jsoncpp)
+       ("lcms" ,lcms)
+       ("libevent" ,libevent)
+       ("libffi" ,libffi)
+       ("libjpeg-turbo" ,libjpeg-turbo)
+       ("libpng" ,libpng)
+       ("libva" ,libva)
+       ("libvpx" ,libvpx)
+       ("libwebp" ,libwebp)
+       ("libx11" ,libx11)
+       ("libxcb" ,libxcb)
+       ("libxcomposite" ,libxcomposite)
+       ("libxcursor" ,libxcursor)
+       ("libxdamage" ,libxdamage)
+       ("libxext" ,libxext)
+       ("libxfixes" ,libxfixes)
+       ("libxi" ,libxi)
+       ("libxml2" ,libxml2)
+       ("libxrandr" ,libxrandr)
+       ("libxrender" ,libxrender)
+       ("libxscrnsaver" ,libxscrnsaver)
+       ("libxslt" ,libxslt)
+       ("libxtst" ,libxtst)
+       ("mesa" ,mesa)
+       ("minizip" ,minizip)
+       ("mit-krb5" ,mit-krb5)
+       ("nss" ,nss)
+       ("openh264" ,openh264)
+       ("openjpeg" ,openjpeg)                          ;PDFium only
+       ("openssl" ,openssl)
+       ("opus" ,opus+custom)
+       ("pango" ,pango)
+       ("pciutils" ,pciutils)
+       ("pulseaudio" ,pulseaudio)
+       ("re2" ,re2)
+       ("snappy" ,snappy)
+       ("speech-dispatcher" ,speech-dispatcher)
+       ("udev" ,eudev)
+       ("valgrind" ,valgrind)
+       ("vulkan-headers" ,vulkan-headers)))
+    (home-page "https://www.chromium.org/")
+    (description
+     "Ungoogled-Chromium is the Chromium web browser, sans integration with
+Google web services.")
+    ;; Chromium is developed as BSD-3, but bundles a large number of third-party
+    ;; components with other licenses.  For full information, see chrome://credits.
+    (license (list license:bsd-3
+                   license:bsd-2
+                   license:expat
+                   license:asl2.0
+                   license:mpl1.1
+                   license:mpl2.0
+                   license:public-domain
+                   license:isc
+                   (license:non-copyleft "chrome://credits"
+                                         "See chrome://credits for more information.")
+                   license:lgpl2.1+))))
