Split initialization_util into a Hermetic Library and a Variations Library

components/task_scheduler_util/variations/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("variations") {
+  sources = [
+    "browser_variations_util.cc",
+    "browser_variations_util.h",
+  ]
+
+  deps = [
+    "//base",
+    "//base:base_static",
+    "//components/task_scheduler_util/initialization",
+    "//components/variations",
+  ]
+}
+
+source_set("unit_tests") {
+  testonly = true
+  sources = [
+    "browser_variations_util_unittest.cc",
+  ]
+  deps = [
+    ":variations",
+    "//base",
+    "//components/variations",
+    "//testing/gtest",
+  ]
+}