disable bootstrap on fedora and epel >=8, use system gn

chromium.spec

@@ -1,3 +1,5 @@
+%define _lto_cflags %{nil}
+
 # set default fuzz=2 for patch
 %global _default_patch_fuzz 2
 
@@ -27,6 +29,13 @@
 # official builds have less debugging and go faster... but we have to shut some things off.
 %global official_build 1
 
+# enable|disble bootstrap for gn
+%if 0%{?rhel} >= 8 || 0%{?fedora}
+%global bootstrap 0
+%else
+%global bootstrap 1
+%endif
+
 # Fancy build status, so we at least know, where we are..
 # %1 where
 # %2 what
@@ -497,9 +506,6 @@ BuildRequires:	minizip-compat-devel
 # RHEL 8 needs to use the compat-minizip (provided by minizip1.2)
 %if 0%{?rhel} >= 8
 BuildRequires:	minizip-compat-devel
-%else
-# RHEL 7 used to have minizip, but as of 7.9, it does not.
-# BuildRequires:	minizip-devel
 %endif
 %endif
 
@@ -508,6 +514,11 @@ BuildRequires:	minizip-compat-devel
 BuildRequires: nodejs
 %endif
 
+# use system gn on fedora and rhel >=8, el7 needs bundle gn
+%if ! %{bootstrap}
+BuildRequires: gn
+%endif
+
 BuildRequires:	nss-devel >= 3.26
 BuildRequires:	pciutils-devel
 BuildRequires:	pulseaudio-libs-devel
@@ -519,8 +530,12 @@ BuildRequires:	pkgconfig(libpipewire-0.3)
 
 # for /usr/bin/appstream-util
 BuildRequires: libappstream-glib
+
+%if %{bootstrap}
 # gn needs these
 BuildRequires: libstdc++-static
+%endif
+
 # Fedora tries to use system libs whenever it can.
 BuildRequires:	bzip2-devel
 BuildRequires:	dbus-glib-devel
@@ -1159,6 +1174,7 @@ FLAGS+=' -Wno-unused-but-set-variable -Wno-unused-result -Wno-unused-function -W
 FLAGS+=' -Wno-unused-const-variable -Wno-unneeded-internal-declaration'
 
 %if %{system_build_flags}
+CFLAGS=${CFLAGS/-g }
 CFLAGS=${CFLAGS/-fexceptions}
 CFLAGS=${CFLAGS/-Wp,-D_GLIBCXX_ASSERTIONS}
 CFLAGS=${CFLAGS/-fcf-protection}
@@ -1369,7 +1385,12 @@ if python3 -c 'import google ; print google.__path__' 2> /dev/null ; then \
     exit 1 ; \
 fi
 
+%if %{bootstrap}
 tools/gn/bootstrap/bootstrap.py --gn-gen-args="$CHROMIUM_CORE_GN_DEFINES $CHROMIUM_BROWSER_GN_DEFINES"
+%else
+cp -a %{_bindir}/gn %{builddir}/
+%endif
+
 %{builddir}/gn --script-executable=%{chromium_pybin} gen --args="$CHROMIUM_CORE_GN_DEFINES $CHROMIUM_BROWSER_GN_DEFINES" %{builddir}
 
 %if %{build_headless}