Split browser-specific and generic code in components/task_scheduler_util/.

components/task_scheduler_util/common/BUILD.gn

 # Copyright 2016 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.
 
-static_library("initialization") {
+static_library("common") {
   sources = [
-    "browser_util.cc",
-    "browser_util.h",
+    "variations_util.cc",
+    "variations_util.h",
   ]
 
   deps = [
     "//base",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
-    "browser_util_unittest.cc",
+    "variations_util_unittest.cc",
   ]
   deps = [
-    ":initialization",
+    ":common",
     "//base",
     "//testing/gtest",
   ]
 }