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/acm2/acm_send_test.cc b/modules/audio_coding/acm2/acm_send_test.cc
index 307c906..09a6c80 100644
--- a/modules/audio_coding/acm2/acm_send_test.cc
+++ b/modules/audio_coding/acm2/acm_send_test.cc
@@ -15,6 +15,7 @@
 #include <string.h>
 
 #include "api/audio_codecs/audio_encoder.h"
+#include "api/audio_codecs/builtin_audio_decoder_factory.h"
 #include "modules/audio_coding/include/audio_coding_module.h"
 #include "modules/audio_coding/neteq/tools/input_audio_file.h"
 #include "modules/audio_coding/neteq/tools/packet.h"
@@ -28,7 +29,12 @@
                                      int source_rate_hz,
                                      int test_duration_ms)
     : clock_(0),
-      acm_(webrtc::AudioCodingModule::Create(&clock_)),
+      acm_(webrtc::AudioCodingModule::Create([this] {
+        AudioCodingModule::Config config;
+        config.clock = &clock_;
+        config.decoder_factory = CreateBuiltinAudioDecoderFactory();
+        return config;
+      }())),
       audio_source_(audio_source),
       source_rate_hz_(source_rate_hz),
       input_block_size_samples_(