Allow an external audio processing module to be used in WebRTC

webrtc/media/engine/nullwebrtcvideoengine_unittest.cc

Index: webrtc/media/engine/nullwebrtcvideoengine_unittest.cc
diff --git a/webrtc/media/engine/nullwebrtcvideoengine_unittest.cc b/webrtc/media/engine/nullwebrtcvideoengine_unittest.cc
index 342b5a89368dc0d9f6ed2b865bcc4f286405149c..e1a2964722171c6db2e09fc61752efd88e367297 100644
--- a/webrtc/media/engine/nullwebrtcvideoengine_unittest.cc
+++ b/webrtc/media/engine/nullwebrtcvideoengine_unittest.cc
@@ -10,6 +10,7 @@
 
 #include "webrtc/media/engine/nullwebrtcvideoengine.h"
 #include "webrtc/media/engine/webrtcvoiceengine.h"
+#include "webrtc/modules/audio_processing/include/audio_processing.h"
 #include "webrtc/test/gtest.h"
 #include "webrtc/test/mock_audio_decoder_factory.h"
 #include "webrtc/test/mock_audio_encoder_factory.h"
@@ -31,7 +32,8 @@ class WebRtcMediaEngineNullVideo
             adm,
             audio_encoder_factory,
             audio_decoder_factory,
-            nullptr) {
+            nullptr,
+            webrtc::AudioProcessing::Create()) {
     video_.SetExternalDecoderFactory(video_decoder_factory);
     video_.SetExternalEncoderFactory(video_encoder_factory);
   }