Update GN build files for new prefs location.

components/variations/BUILD.gn

 # Copyright 2014 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.
 
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
 source_set("variations") {
   sources = [
@@ skipping 50 matching lines @@
   if (is_android || is_ios) {
     sources += [
       "variations_request_scheduler_mobile.cc",
       "variations_request_scheduler_mobile.h",
     ]
   }
 
   deps = [
     "proto",
     "//base",
-    "//base:prefs",
     "//components/crash/core/common",
+    "//components/prefs",
     "//crypto",
     "//third_party/mt19937ar",
     "//third_party/protobuf:protobuf_lite",
     "//third_party/zlib:compression_utils",
   ]
 
   if (is_android) {
     deps += [ ":jni" ]
   }
 }
@@ skipping 28 matching lines @@
   ]
 
   if (is_android || is_ios) {
     sources += [ "variations_request_scheduler_mobile_unittest.cc" ]
   }
 
   deps = [
     ":variations",
     "net",
     "proto",
-    "//base:prefs_test_support",
     "//base/test:test_support",
+    "//components/prefs:test_support",
     "//testing/gtest",
     "//third_party/zlib:compression_utils",
   ]
 }