Restructure protobuf targets to fit with downstream requirements.

webrtc/modules/audio_coding/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("audio_coding.gni")
@@ skipping 1306 matching lines @@
     if (is_ios) {
       deps += [ ":audio_decoder_unittests_bundle_data" ]
     }
   }  # audio_decoder_unittests
 
   if (rtc_enable_protobuf) {
     proto_library("neteq_unittest_proto") {
       sources = [
         "neteq/neteq_unittest.proto",
       ]
-      proto_out_dir = "webrtc/audio_coding/neteq"
+      proto_out_dir = "webrtc/modules/audio_coding/neteq"
     }
 
     rtc_static_library("rtc_event_log_source") {
       testonly = true
 
       # TODO(kjellander): Remove (bugs.webrtc.org/6828)
       # Needs call.h to be moved to webrtc/api first.
       check_includes = false
 
       sources = [
@@ skipping 768 matching lines @@
 # webrtc/api/audio_codecs:builtin_audio_decoder_factory instead.
 # TODO(kwiberg): Remove this.
 rtc_source_set("builtin_audio_decoder_factory") {
   sources = [
     "codecs/builtin_audio_decoder_factory.h",
   ]
   deps = [
     "../../api/audio_codecs:builtin_audio_decoder_factory",
   ]
 }