diff --git a/build/linux/unbundle/icu.gn b/build/linux/unbundle/icu.gn
new file mode 100644
index 00000000000..9e54d4efe4e
--- /dev/null
+++ b/build/linux/unbundle/icu.gn
@@ -0,0 +1,262 @@
+# Copyright 2016 The Chromium Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/linux/pkg_config.gni")
+import("//build/shim_headers.gni")
+
+group("icu") {
+  public_deps = [
+    ":icui18n",
+    ":icuuc",
+  ]
+}
+
+config("icu_config") {
+  defines = [
+    "USING_SYSTEM_ICU=1",
+    "ICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_STATIC",
+
+    # U_EXPORT (defined in unicode/platform.h) is used to set public visibility
+    # on classes through the U_COMMON_API and U_I18N_API macros (among others).
+    # When linking against the system ICU library, we want its symbols to have
+    # public LTO visibility. This disables CFI checks for the ICU classes and
+    # allows whole-program optimization to be applied to the rest of Chromium.
+    #
+    # Both U_COMMON_API and U_I18N_API macros would be defined to U_EXPORT only
+    # when U_COMBINED_IMPLEMENTATION is defined (see unicode/utypes.h). Because
+    # we override the default system UCHAR_TYPE (char16_t), it is not possible
+    # to use U_COMBINED_IMPLEMENTATION at this moment, meaning the U_COMMON_API
+    # and U_I18N_API macros are set to U_IMPORT which is an empty definition.
+    #
+    # Until building with UCHAR_TYPE=char16_t is supported, one way to apply
+    # public visibility (and thus public LTO visibility) to all ICU classes is
+    # to define U_IMPORT to have the same value as U_EXPORT. For more details,
+    # please see: https://crbug.com/822820
+    "U_IMPORT=U_EXPORT",
+  ]
+}
+
+pkg_config("system_icui18n") {
+  packages = [ "icu-i18n" ]
+}
+
+pkg_config("system_icuuc") {
+  packages = [ "icu-uc" ]
+}
+
+source_set("icui18n") {
+  public_deps = [ ":icui18n_shim" ]
+  public_configs = [
+    ":icu_config",
+    ":system_icui18n",
+  ]
+}
+
+source_set("icuuc") {
+  public_deps = [ ":icuuc_shim" ]
+  public_configs = [
+    ":icu_config",
+    ":system_icuuc",
+  ]
+}
+
+group("icui18n_hidden_visibility") {
+  public_deps = [ ":icui18n" ]
+}
+
+group("icuuc_hidden_visibility") {
+  public_deps = [ ":icuuc" ]
+}
+
+shim_headers("icui18n_shim") {
+  root_path = "source/i18n"
+  headers = [
+    # This list can easily be updated using the commands below:
+    # cd third_party/icu/source/i18n
+    # find unicode -iname '*.h' -printf '    "%p",\n' | LC_ALL=C sort -u
+    "unicode/alphaindex.h",
+    "unicode/basictz.h",
+    "unicode/calendar.h",
+    "unicode/choicfmt.h",
+    "unicode/coleitr.h",
+    "unicode/coll.h",
+    "unicode/compactdecimalformat.h",
+    "unicode/curramt.h",
+    "unicode/currpinf.h",
+    "unicode/currunit.h",
+    "unicode/datefmt.h",
+    "unicode/dcfmtsym.h",
+    "unicode/decimfmt.h",
+    "unicode/dtfmtsym.h",
+    "unicode/dtitvfmt.h",
+    "unicode/dtitvinf.h",
+    "unicode/dtptngen.h",
+    "unicode/dtrule.h",
+    "unicode/fieldpos.h",
+    "unicode/fmtable.h",
+    "unicode/format.h",
+    "unicode/fpositer.h",
+    "unicode/gender.h",
+    "unicode/gregocal.h",
+    "unicode/listformatter.h",
+    "unicode/measfmt.h",
+    "unicode/measunit.h",
+    "unicode/measure.h",
+    "unicode/msgfmt.h",
+    "unicode/numfmt.h",
+    "unicode/numsys.h",
+    "unicode/plurfmt.h",
+    "unicode/plurrule.h",
+    "unicode/rbnf.h",
+    "unicode/rbtz.h",
+    "unicode/regex.h",
+    "unicode/region.h",
+    "unicode/reldatefmt.h",
+    "unicode/scientificnumberformatter.h",
+    "unicode/search.h",
+    "unicode/selfmt.h",
+    "unicode/simpletz.h",
+    "unicode/smpdtfmt.h",
+    "unicode/sortkey.h",
+    "unicode/stsearch.h",
+    "unicode/tblcoll.h",
+    "unicode/timezone.h",
+    "unicode/tmunit.h",
+    "unicode/tmutamt.h",
+    "unicode/tmutfmt.h",
+    "unicode/translit.h",
+    "unicode/tzfmt.h",
+    "unicode/tznames.h",
+    "unicode/tzrule.h",
+    "unicode/tztrans.h",
+    "unicode/ucal.h",
+    "unicode/ucol.h",
+    "unicode/ucoleitr.h",
+    "unicode/ucsdet.h",
+    "unicode/udat.h",
+    "unicode/udateintervalformat.h",
+    "unicode/udatpg.h",
+    "unicode/ufieldpositer.h",
+    "unicode/uformattable.h",
+    "unicode/ugender.h",
+    "unicode/ulocdata.h",
+    "unicode/umsg.h",
+    "unicode/unirepl.h",
+    "unicode/unum.h",
+    "unicode/unumsys.h",
+    "unicode/upluralrules.h",
+    "unicode/uregex.h",
+    "unicode/uregion.h",
+    "unicode/ureldatefmt.h",
+    "unicode/usearch.h",
+    "unicode/uspoof.h",
+    "unicode/utmscale.h",
+    "unicode/utrans.h",
+    "unicode/vtzone.h",
+  ]
+}
+
+shim_headers("icuuc_shim") {
+  root_path = "source/common"
+  headers = [
+    # This list can easily be updated using the commands below:
+    # cd third_party/icu/source/common
+    # find unicode -iname '*.h' -printf '    "%p",\n' | LC_ALL=C sort -u
+    "unicode/appendable.h",
+    "unicode/brkiter.h",
+    "unicode/bytestream.h",
+    "unicode/bytestrie.h",
+    "unicode/bytestriebuilder.h",
+    "unicode/caniter.h",
+    "unicode/casemap.h",
+    "unicode/char16ptr.h",
+    "unicode/chariter.h",
+    "unicode/dbbi.h",
+    "unicode/docmain.h",
+    "unicode/dtintrv.h",
+    "unicode/edits.h",
+    "unicode/enumset.h",
+    "unicode/errorcode.h",
+    "unicode/filteredbrk.h",
+    "unicode/icudataver.h",
+    "unicode/icuplug.h",
+    "unicode/idna.h",
+    "unicode/localematcher.h",
+    "unicode/localpointer.h",
+    "unicode/locdspnm.h",
+    "unicode/locid.h",
+    "unicode/messagepattern.h",
+    "unicode/normalizer2.h",
+    "unicode/normlzr.h",
+    "unicode/parseerr.h",
+    "unicode/parsepos.h",
+    "unicode/platform.h",
+    "unicode/ptypes.h",
+    "unicode/putil.h",
+    "unicode/rbbi.h",
+    "unicode/rep.h",
+    "unicode/resbund.h",
+    "unicode/schriter.h",
+    "unicode/simpleformatter.h",
+    "unicode/std_string.h",
+    "unicode/strenum.h",
+    "unicode/stringpiece.h",
+    "unicode/stringtriebuilder.h",
+    "unicode/symtable.h",
+    "unicode/ubidi.h",
+    "unicode/ubiditransform.h",
+    "unicode/ubrk.h",
+    "unicode/ucasemap.h",
+    "unicode/ucat.h",
+    "unicode/uchar.h",
+    "unicode/ucharstrie.h",
+    "unicode/ucharstriebuilder.h",
+    "unicode/uchriter.h",
+    "unicode/uclean.h",
+    "unicode/ucnv.h",
+    "unicode/ucnv_cb.h",
+    "unicode/ucnv_err.h",
+    "unicode/ucnvsel.h",
+    "unicode/uconfig.h",
+    "unicode/ucurr.h",
+    "unicode/udata.h",
+    "unicode/udisplaycontext.h",
+    "unicode/uenum.h",
+    "unicode/uidna.h",
+    "unicode/uiter.h",
+    "unicode/uldnames.h",
+    "unicode/ulistformatter.h",
+    "unicode/uloc.h",
+    "unicode/umachine.h",
+    "unicode/umisc.h",
+    "unicode/unifilt.h",
+    "unicode/unifunct.h",
+    "unicode/unimatch.h",
+    "unicode/uniset.h",
+    "unicode/unistr.h",
+    "unicode/unorm.h",
+    "unicode/unorm2.h",
+    "unicode/uobject.h",
+    "unicode/urename.h",
+    "unicode/urep.h",
+    "unicode/ures.h",
+    "unicode/uscript.h",
+    "unicode/uset.h",
+    "unicode/usetiter.h",
+    "unicode/ushape.h",
+    "unicode/usprep.h",
+    "unicode/ustring.h",
+    "unicode/ustringtrie.h",
+    "unicode/utext.h",
+    "unicode/utf.h",
+    "unicode/utf16.h",
+    "unicode/utf32.h",
+    "unicode/utf8.h",
+    "unicode/utf_old.h",
+    "unicode/utrace.h",
+    "unicode/utypes.h",
+    "unicode/uvernum.h",
+    "unicode/uversion.h",
+  ]
+}
diff --git a/build/linux/unbundle/replace_gn_files.py b/build/linux/unbundle/replace_gn_files.py
new file mode 100755
index 00000000000..1aed7bca99d
--- /dev/null
+++ b/build/linux/unbundle/replace_gn_files.py
@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+# Copyright 2016 The Chromium Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Replaces GN files in tree with files from here that
+make the build use system libraries.
+"""
+
+import argparse
+import os
+import shutil
+import sys
+
+
+REPLACEMENTS = {
+  'icu': 'third_party/icu/BUILD.gn',
+  'protobuf': 'build/secondary/third_party/protobuf/BUILD.gn',
+  'zlib': 'third_party/zlib/BUILD.gn',
+}
+
+
+def DoMain(argv):
+  my_dirname = os.path.dirname(__file__)
+  source_tree_root = os.path.abspath(
+    os.path.join(my_dirname, '..', '..', '..'))
+
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--system-libraries', nargs='*', default=[])
+  parser.add_argument('--undo', action='store_true')
+
+  args = parser.parse_args(argv)
+
+  handled_libraries = set()
+  for lib, path in REPLACEMENTS.items():
+    if lib not in args.system_libraries:
+      continue
+    handled_libraries.add(lib)
+
+    if args.undo:
+      # Restore original file, and also remove the backup.
+      # This is meant to restore the source tree to its original state.
+      os.rename(os.path.join(source_tree_root, path + '.orig'),
+                os.path.join(source_tree_root, path))
+    else:
+      # Create a backup copy for --undo.
+      shutil.copyfile(os.path.join(source_tree_root, path),
+                      os.path.join(source_tree_root, path + '.orig'))
+
+      # Copy the GN file from directory of this script to target path.
+      shutil.copyfile(os.path.join(my_dirname, '%s.gn' % lib),
+                      os.path.join(source_tree_root, path))
+
+  unhandled_libraries = set(args.system_libraries) - handled_libraries
+  if unhandled_libraries:
+    print('Unrecognized system libraries requested: %s' % ', '.join(
+        sorted(unhandled_libraries)), file=sys.stderr)
+    return 1
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(DoMain(sys.argv[1:]))
diff --git a/build/linux/unbundle/zlib.gn b/build/linux/unbundle/zlib.gn
new file mode 100644
index 00000000000..fa2bbffd25f
--- /dev/null
+++ b/build/linux/unbundle/zlib.gn
@@ -0,0 +1,63 @@
+# Copyright 2016 The Chromium Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/shim_headers.gni")
+
+shim_headers("zlib_shim") {
+  root_path = "."
+  headers = [ "zlib.h" ]
+  additional_includes = [ "third_party" ]
+
+}
+
+config("system_zlib") {
+  defines = [ "USE_SYSTEM_ZLIB=1" ]
+}
+
+config("zlib_config") {
+  configs = [ ":system_zlib" ]
+}
+
+source_set("zlib") {
+  public_deps = [ ":zlib_shim" ]
+  libs = [ "z" ]
+  public_configs = [ ":system_zlib" ]
+}
+
+shim_headers("minizip_shim") {
+  root_path = "contrib"
+  headers = [
+    "minizip/crypt.h",
+    "minizip/ioapi.h",
+    "minizip/iowin32.h",
+    "minizip/mztools.h",
+    "minizip/unzip.h",
+    "minizip/zip.h",
+  ]
+}
+
+source_set("minizip") {
+  deps = [ ":minizip_shim" ]
+  libs = [ "minizip" ]
+}
+
+static_library("zip") {
+  sources = [
+    "google/zip.cc",
+    "google/zip.h",
+    "google/zip_internal.cc",
+    "google/zip_internal.h",
+    "google/zip_reader.cc",
+    "google/zip_reader.h",
+  ]
+  deps = [ ":minizip" ]
+}
+
+static_library("compression_utils") {
+  sources = [
+    "google/compression_utils.cc",
+    "google/compression_utils.h",
+  ]
+  deps = [ ":zlib" ]
+}
diff --git a/build/shim_headers.gni b/build/shim_headers.gni
index dc57d12ed0c..1d24e0ad00e 100644
--- a/build/shim_headers.gni
+++ b/build/shim_headers.gni
@@ -7,6 +7,11 @@ template("shim_headers") {
   shim_headers_path = "${root_gen_dir}/shim_headers/${target_name}"
   config(config_name) {
     include_dirs = [ shim_headers_path ]
+    if (defined(invoker.additional_includes)) {
+      foreach(i, invoker.additional_includes) {
+        include_dirs += [ shim_headers_path + "/" + i ]
+      }
+    }
   }
   action(action_name) {
     script = "//tools/generate_shim_headers.py"
@@ -26,11 +31,12 @@ template("shim_headers") {
     args += invoker.headers
     outputs = []
     foreach(h, invoker.headers) {
-      outputs += [ shim_headers_path + "/" + rebase_path(invoker.root_path,"//") + "/" + h ]
+      outputs += [ shim_headers_path + "/" +
+                   rebase_path(invoker.root_path, "//") + "/" + h ]
     }
   }
   group(target_name) {
-    deps = [ ":${action_name}" ]
+    public_deps = [ ":${action_name}" ]
     all_dependent_configs = [ ":${config_name}" ]
   }
 }