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

webrtc/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("../build/webrtc.gni")
+import("../webrtc.gni")
 
 group("tools") {
   # This target shall build all targets in tools/.
   testonly = true
 
   public_deps = [
     ":command_line_parser",
     ":frame_analyzer",
     ":frame_editor",
     ":psnr_ssim_analyzer",
@@ skipping 306 matching lines @@
       ]
       outputs = [
         "$root_build_dir/{{source_file_part}}",
       ]
       deps = [
         "../logging:rtc_event_log_proto",
       ]
     }
   }
 }