GN: Move variables from //build_overrides/webrtc.gni to //webrtc/build/webrtc.gni

webrtc/test/fuzzers/BUILD.gn

 # Copyright (c) 2015 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("../../build/webrtc.gni")
 import("//build/config/features.gni")
-import("//build_overrides/webrtc.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 
 rtc_static_library("webrtc_fuzzer_main") {
   sources = [
     "webrtc_fuzzer_main.cc",
   ]
   deps = [
     "../../system_wrappers:field_trial_default",
     "../../system_wrappers:metrics_default",
     "//testing/libfuzzer:libfuzzer_main",
@@ skipping 210 matching lines @@
 
   webrtc_fuzzer_test("pseudotcp_parser_fuzzer") {
     sources = [
       "pseudotcp_parser_fuzzer.cc",
     ]
     deps = [
       "../../p2p:rtc_p2p",
     ]
   }
 }