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

chromecast/base/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("//chrome/version.gni")  # TODO layering violation!
+import("//build/util/process_version.gni")
 import("//chromecast/chromecast.gni")
 import("//testing/test.gni")
 
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
 declare_args() {
   # Denotes the type of Cast product. This is #defined as CAST_PRODUCT_TYPE in
   # version.h. This is an integer in the range [0-4].
@@ skipping 177 matching lines @@
       "//base",
       "//chromecast/public",
     ]
   }
 }
 
 process_version("cast_version") {
   template_file = "version.h.in"
   output = "$target_gen_dir/version.h"
 
+  sources = [
+    "//chrome/VERSION",
+  ]
   extra_args = [
     "-e",
     "VERSION_FULL=\"%s.%s.%s.%s\"%(MAJOR,MINOR,BUILD,PATCH)",
     "-e",
     "CAST_BUILD_RELEASE=\"$cast_build_release\"",
     "-e",
     "CAST_BUILD_INCREMENTAL=\"$cast_build_incremental\"",
     "-e",
     "CAST_PRODUCT_TYPE=$cast_product_type",
   ]
@@ skipping 31 matching lines @@
       "$java_src_dir/org/chromium/chromecast/base/ChromecastConfigAndroid.java",
       "$java_src_dir/org/chromium/chromecast/base/DumpstateWriter.java",
       "$java_src_dir/org/chromium/chromecast/base/SystemTimeChangeNotifierAndroid.java",
     ]
 
     deps = [
       "//base:base_java",
     ]
   }
 }