AudioCodingModule::Create(): Require caller to supply an AudioDecoderFactory

So that we don't have to be capable of creating one ourselves, which
requires a dependency on the audio decoders.

BUG=webrtc:5801, webrtc:8396

Change-Id: I80749ec3b86cba73994307046d05964f59167d44
Reviewed-on: https://webrtc-review.googlesource.com/18440
Commit-Queue: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Oskar Sundbom <ossu@webrtc.org>
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22774}
diff --git a/modules/audio_coding/test/TestVADDTX.cc b/modules/audio_coding/test/TestVADDTX.cc
index 8064448..5865638 100644
--- a/modules/audio_coding/test/TestVADDTX.cc
+++ b/modules/audio_coding/test/TestVADDTX.cc
@@ -12,6 +12,7 @@
 
 #include <string>
 
+#include "api/audio_codecs/builtin_audio_decoder_factory.h"
 #include "modules/audio_coding/codecs/audio_format_conversion.h"
 #include "modules/audio_coding/test/PCMFile.h"
 #include "modules/audio_coding/test/utility.h"
@@ -62,8 +63,10 @@
 }
 
 TestVadDtx::TestVadDtx()
-    : acm_send_(AudioCodingModule::Create()),
-      acm_receive_(AudioCodingModule::Create()),
+    : acm_send_(AudioCodingModule::Create(
+          AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory()))),
+      acm_receive_(AudioCodingModule::Create(
+          AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory()))),
       channel_(new Channel),
       monitor_(new ActivityMonitor) {
   EXPECT_EQ(0, acm_send_->RegisterTransportCallback(channel_.get()));