gn: Generalize process_version() and move it to build/util

chrome/chrome_watcher/BUILD.gn

Index: chrome/chrome_watcher/BUILD.gn
diff --git a/chrome/chrome_watcher/BUILD.gn b/chrome/chrome_watcher/BUILD.gn
index 8a3e48a931d97228f6f061bc1a5b90a3c9a7dd3e..0d9265bd300b231f72c7f5421abad1bf3df09637 100644
--- a/chrome/chrome_watcher/BUILD.gn
+++ b/chrome/chrome_watcher/BUILD.gn
@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//chrome/version.gni")
+import("//chrome/process_version_rc_template.gni")
 import("//testing/test.gni")
 
 source_set("client") {
@@ -47,8 +47,7 @@ group("kasko_util") {
   ]
 }
 
-process_version("chrome_watcher_resources") {
-  template_file = chrome_version_rc_template
+process_version_rc_template("chrome_watcher_resources") {
   sources = [
     "chrome_watcher.ver",
   ]