GN: Exclude some packages that are not used on CrOS

build/config/linux/BUILD.gn

Index: build/config/linux/BUILD.gn
diff --git a/build/config/linux/BUILD.gn b/build/config/linux/BUILD.gn
index 77c4d672f7459bd594bfa0d68bbf6161ced71e4a..49d78633794840e4ad03847413a54c3d5da1b39a 100644
--- a/build/config/linux/BUILD.gn
+++ b/build/config/linux/BUILD.gn
@@ -33,16 +33,6 @@ pkg_config("glib") {
   packages = [ "glib-2.0", "gmodule-2.0", "gobject-2.0", "gthread-2.0" ]
 }
 
-pkg_config("gtk") {
-  # Gtk requires gmodule, but it does not list it as a dependency in some
-  # misconfigured systems.
-  packages = [ "gmodule-2.0", "gtk+-2.0", "gthread-2.0" ]
-}
-
-pkg_config("gtkprint") {
-  packages = [ "gtk+-unix-print-2.0" ]
-}
-
 pkg_config("pangocairo") {
   packages = [ "pangocairo" ]
 }
@@ -61,10 +51,6 @@ pkg_config("dbus") {
   packages = [ "dbus-1" ]
 }
 
-pkg_config("gnome_keyring") {
-  packages = [ "gnome-keyring-1" ]
-}
-
 if (use_evdev_gestures) {
   pkg_config("libevdev-cros") {
     packages = [ "libevdev-cros" ]
@@ -124,9 +110,26 @@ config("libresolv") {
   libs = [ "resolv" ]
 }
 
-pkg_config("gconf") {
-  packages = [ "gconf-2.0" ]
-  defines = [ "USE_GCONF" ]
+# CrOS doesn't install GTK, gconf or any gnome packages.
+if (!is_chromeos) {
+  pkg_config("gtk") {
+    # Gtk requires gmodule, but it does not list it as a dependency in some
+    # misconfigured systems.
+    packages = [ "gmodule-2.0", "gtk+-2.0", "gthread-2.0" ]
+  }
+
+  pkg_config("gtkprint") {
+    packages = [ "gtk+-unix-print-2.0" ]
+  }
+
+  pkg_config("gnome_keyring") {
+    packages = [ "gnome-keyring-1" ]
+  }
+
+  pkg_config("gconf") {
+    packages = [ "gconf-2.0" ]
+    defines = [ "USE_GCONF" ]
+  }
 }
 
 # If brlapi isn't needed, don't require it to be installed.