Revert of Moving webrtc.gni up one level from build/

webrtc/modules/bitrate_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")
+import("../../build/webrtc.gni")
 
 rtc_static_library("bitrate_controller") {
   # TODO(mbonadei): Remove (bugs.webrtc.org/6828)
   # Errors on cyclic dependency with:
   # congestion_controller:congestion_controller if enabled.
   check_includes = false
 
   sources = [
     "bitrate_controller_impl.cc",
     "bitrate_controller_impl.h",
@@ skipping 36 matching lines @@
       "../../test:test_support",
       "../remote_bitrate_estimator:remote_bitrate_estimator",
       "//testing/gmock",
     ]
     if (!build_with_chromium && is_clang) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }
   }
 }