Added an empty AudioTransportProxy to AudioState.

webrtc/call/bitrate_estimator_tests.cc

Index: webrtc/call/bitrate_estimator_tests.cc
diff --git a/webrtc/call/bitrate_estimator_tests.cc b/webrtc/call/bitrate_estimator_tests.cc
index 80949baba4d5933d672511385076e4c8b7ae5560..ff72c6688a61a20f38c31c15167281b2e95ba21c 100644
--- a/webrtc/call/bitrate_estimator_tests.cc
+++ b/webrtc/call/bitrate_estimator_tests.cc
@@ -18,6 +18,7 @@
 #include "webrtc/base/logging.h"
 #include "webrtc/base/thread_annotations.h"
 #include "webrtc/call.h"
+#include "webrtc/modules/audio_device/include/mock_audio_device.h"
 #include "webrtc/system_wrappers/include/critical_section_wrapper.h"
 #include "webrtc/system_wrappers/include/trace.h"
 #include "webrtc/test/call_test.h"
@@ -109,6 +110,8 @@ class BitrateEstimatorTest : public test::CallTest {
   virtual void SetUp() {
     AudioState::Config audio_state_config;
     audio_state_config.voice_engine = &mock_voice_engine_;
+    ON_CALL(mock_voice_engine_, audio_device_module())
+        .WillByDefault(Return(&mock_audio_device_));

[stefan-webrtc, 2016/11/03 14:33:53]

Could you try to remove everything audio related here instead? I don't think it
uses it any longer.

[aleloi, 2016/11/08 11:46:41]

I've done it in another CL; I'll rebase this one as soon as
https://codereview.webrtc.org/2479383003/has landed.

     Call::Config config(&event_log_);
     config.audio_state = AudioState::Create(audio_state_config);
     receiver_call_.reset(Call::Create(config));
@@ -252,6 +255,7 @@ class BitrateEstimatorTest : public test::CallTest {
   };
 
   testing::NiceMock<test::MockVoiceEngine> mock_voice_engine_;
+  testing::NiceMock<webrtc::test::MockAudioDeviceModule> mock_audio_device_;
   LogObserver receiver_log_;
   std::unique_ptr<test::DirectTransport> send_transport_;
   std::unique_ptr<test::DirectTransport> receive_transport_;