gn: Generalize process_version() and move it to build/util (take #2)

chrome/common/BUILD.gn

Index: chrome/common/BUILD.gn
diff --git a/chrome/common/BUILD.gn b/chrome/common/BUILD.gn
index 3d768457c2c9f6e104c84ba1f7615dc4e31ff110..d718de2a03ca6cfcf09efdfc6c59709ef6ed9b83 100644
--- a/chrome/common/BUILD.gn
+++ b/chrome/common/BUILD.gn
@@ -3,8 +3,9 @@
 # found in the LICENSE file.
 
 import("//build/buildflag_header.gni")
+import("//build/util/process_version.gni")
 import("//chrome/common/features.gni")
-import("//chrome/version.gni")
+import("//chrome/process_version_rc_template.gni")  # For branding_file_path.
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//tools/grit/grit_rule.gni")
 
@@ -510,8 +511,11 @@ process_version("version_header") {
   # currently depends on this.
   #visibility = [ ":*" ]
 
-  # This one just uses the custom template and no separate sources.
-  sources = []
+  sources = [
+    "//build/util/LASTCHANGE",
+    "//chrome/VERSION",
+    branding_file_path,
+  ]
   template_file = "chrome_version.h.in"
 
   output = "$target_gen_dir/chrome_version.h"