Add Linux build packaging targets to GN

build/config/chrome_build.gni

Index: build/config/chrome_build.gni
diff --git a/build/config/chrome_build.gni b/build/config/chrome_build.gni
index c2132c4a1624c255ca9e6c23a33cd443372f45d9..de6c2c5ff468c1afad70d9289dd09ac1ef9005a7 100644
--- a/build/config/chrome_build.gni
+++ b/build/config/chrome_build.gni
@@ -17,3 +17,11 @@ declare_args() {
   # on Windows.
   is_multi_dll_chrome = is_win && !is_component_build
 }
+
+# Refers to the subdirectory for branding in various places including
+# chrome/app/theme.
+if (is_chrome_branded) {
+  branding_path_component = "google_chrome"
+} else {
+  branding_path_component = "chromium"
+}