Add webrtc_perf_tests to BUILD.gn

webrtc/modules/audio_processing/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("//build/config/arm.gni")
 import("//third_party/protobuf/proto_library.gni")
@@ skipping 301 matching lines @@
     } else {
       defines = [ "WEBRTC_AEC_DEBUG_DUMP=0" ]
     }
   }
 }
 
 if (rtc_include_tests) {
   source_set("audioproc_test_utils") {
     testonly = true
     sources = [
+      "test/audio_buffer_tools.cc",
+      "test/audio_buffer_tools.h",
       "test/test_utils.cc",
       "test/test_utils.h",
     ]
 
     configs += [ "../..:common_config" ]
     public_configs = [ "../..:common_inherited_config" ]
 
     if (is_clang) {
       # Suppress warnings from the Chromium Clang plugins (bugs.webrtc.org/163).
       configs -= [ "//build/config/clang:find_bad_constructs" ]
@@ skipping 18 matching lines @@
         "test/protobuf_utils.cc",
         "test/protobuf_utils.h",
       ]
 
       deps = [
         ":audioproc_unittest_proto",
       ]
     }
   }
 }