Use relative paths in GN files.

webrtc/modules/congestion_controller/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("../../webrtc.gni")
 
@@ skipping 52 matching lines @@
 }
 
 if (rtc_include_tests) {
   rtc_source_set("congestion_controller_unittests") {
     testonly = true
 
     # Skip restricting visibility on mobile platforms since the tests on those
     # gets additional generated targets which would require many lines here to
     # cover (which would be confusing to read and hard to maintain).
     if (!is_android && !is_ios) {
-      visibility = [ "//webrtc/modules:modules_unittests" ]
+      visibility = [ "..:modules_unittests" ]
     }
     sources = [
       "congestion_controller_unittest.cc",
       "congestion_controller_unittests_helper.cc",
       "congestion_controller_unittests_helper.h",
       "delay_based_bwe_unittest.cc",
       "delay_based_bwe_unittest_helper.cc",
       "delay_based_bwe_unittest_helper.h",
       "median_slope_estimator_unittest.cc",
       "probe_bitrate_estimator_unittest.cc",
@@ skipping 27 matching lines @@
     sources = [
       "include/mock/mock_congestion_observer.h",
       "include/mock/mock_send_side_congestion_controller.h",
     ]
     deps = [
       ":congestion_controller",
       "../../test:test_support",
     ]
   }
 }