Use relative paths in GN files.

webrtc/rtc_tools/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("//third_party/protobuf/proto_library.gni")
 import("../webrtc.gni")
@@ skipping 257 matching lines @@
       "../modules:module_api",
       "../modules/audio_processing",
       "../system_wrappers:metrics_default",
       "../test:test_support",
       "//build/win:default_exe_manifest",
       "//testing/gtest",
     ]
   }
 
   tools_unittests_resources = [
-    "//resources/foreman_cif.yuv",
-    "//resources/reference_less_video_test_file.y4m",
-    "//resources/video_quality_analysis_frame.txt",
+    "../../resources/foreman_cif.yuv",
+    "../../resources/reference_less_video_test_file.y4m",
+    "../../resources/video_quality_analysis_frame.txt",
   ]
 
   if (is_ios) {
     bundle_data("tools_unittests_bundle_data") {
       testonly = true
       sources = tools_unittests_resources
       outputs = [
         "{{bundle_resources_dir}}/{{source_file_part}}",
       ]
     }
@@ skipping 50 matching lines @@
       ]
       outputs = [
         "$root_build_dir/{{source_file_part}}",
       ]
       deps = [
         "../logging:rtc_event_log_proto",
       ]
     }
   }
 }