Update GN build files for new prefs location.

base/BUILD.gn

 # Copyright (c) 2013 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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 1447 matching lines @@
         "check_example.cc",
       ]
       deps = [
         ":base",
         "//build/config/sanitizers:deps",
       ]
     }
   }
 }
 
-# TODO(brettw) remove these forwarding targets when all references to prefs are
-# updated to point to components.
-group("prefs") {
-  public_deps = [
-    "//components/prefs",
-  ]
-}
-group("prefs_test_support") {
-  testonly = true
-  public_deps = [
-    "//components/prefs:test_support",
-  ]
-}
-
 source_set("message_loop_tests") {
   testonly = true
   sources = [
     "message_loop/message_loop_test.cc",
     "message_loop/message_loop_test.h",
   ]
 
   deps = [
     ":base",
     "//testing/gtest",
@@ skipping 569 matching lines @@
 
   # GYP: //base.gyp:base_java_unittest_support
   android_library("base_java_unittest_support") {
     deps = [
       ":base_java",
     ]
     java_files =
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }