Initialize default audio device ID with explicit device ID.

content/renderer/media/user_media_client_impl_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/user_media_client_impl.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <utility>
 #include <vector>
 
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/child/child_process.h"
 #include "content/common/media/media_devices.h"
 #include "content/renderer/media/media_stream.h"
 #include "content/renderer/media/media_stream_audio_source.h"
 #include "content/renderer/media/media_stream_track.h"
 #include "content/renderer/media/mock_constraint_factory.h"
 #include "content/renderer/media/mock_media_stream_dispatcher.h"
 #include "content/renderer/media/mock_media_stream_video_source.h"
 #include "content/renderer/media/webrtc/mock_peer_connection_dependency_factory.h"
+#include "media/audio/audio_device_description.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/platform/WebMediaDeviceInfo.h"
 #include "third_party/WebKit/public/platform/WebMediaStream.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
 #include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/WebVector.h"
 #include "third_party/WebKit/public/web/WebHeap.h"
 
@@ skipping 858 matching lines @@
   TestValidRequestWithConstraints(audio_constraints, video_constraints,
                                   kFakeAudioInputDeviceId1,
                                   kFakeVideoInputDeviceId1);
 }
 
 TEST_F(UserMediaClientImplTest, CreateWithAllOptionalInvalidDeviceId) {
   blink::WebMediaConstraints audio_constraints =
       CreateDeviceConstraints(nullptr, kInvalidDeviceId, kInvalidDeviceId);
   blink::WebMediaConstraints video_constraints =
       CreateDeviceConstraints(nullptr, kInvalidDeviceId, kInvalidDeviceId);
-  // MockMediaStreamDispatcher uses empty string as default audio device ID.
   // MockMediaDevicesDispatcher uses the first device in the enumeration as
   // default video device ID.
-  TestValidRequestWithConstraints(audio_constraints, video_constraints,
-                                  std::string(), kFakeVideoInputDeviceId1);
+  TestValidRequestWithConstraints(
+      audio_constraints, video_constraints,
+      std::string(media::AudioDeviceDescription::kDefaultDeviceId),
+      kFakeVideoInputDeviceId1);
 }
 
 TEST_F(UserMediaClientImplTest, CreateWithFacingModeUser) {
   blink::WebMediaConstraints audio_constraints =
       CreateDeviceConstraints(kFakeAudioInputDeviceId1);
   blink::WebMediaConstraints video_constraints =
       CreateFacingModeConstraints("user");
   // kFakeVideoInputDeviceId1 has user facing mode.
   TestValidRequestWithConstraints(audio_constraints, video_constraints,
                                   kFakeAudioInputDeviceId1,
                                   kFakeVideoInputDeviceId1);
 }
 
 TEST_F(UserMediaClientImplTest, CreateWithFacingModeEnvironment) {
   blink::WebMediaConstraints audio_constraints =
       CreateDeviceConstraints(kFakeAudioInputDeviceId1);
   blink::WebMediaConstraints video_constraints =
       CreateFacingModeConstraints("environment");
   // kFakeVideoInputDeviceId2 has environment facing mode.
   TestValidRequestWithConstraints(audio_constraints, video_constraints,
                                   kFakeAudioInputDeviceId1,
                                   kFakeVideoInputDeviceId2);
 }
 
 }  // namespace content