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

components/version_info/BUILD.gn

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/chrome_build.gni")
-import("//chrome/version.gni")
+import("//build/util/process_version.gni")
 
 declare_args() {
   use_unofficial_version_number = !is_chrome_branded
 }
 
 static_library("version_info") {
   sources = [
     "version_info.cc",
     "version_info.h",
   ]
 
   deps = [
     ":generate_version_info",
     "//base",
     "//components/strings",
   ]
 
   if (use_unofficial_version_number) {
     defines = [ "USE_UNOFFICIAL_VERSION_NUMBER" ]
     deps += [ "//ui/base" ]
   }
 }
 
 process_version("generate_version_info") {
   template_file = "version_info_values.h.version"
+  sources = [
+    "//build/util/LASTCHANGE",
+    "//chrome/VERSION",
+    branding_file_path,
+  ]
   output = "$target_gen_dir/version_info_values.h"
 }