[Chromecast] Fix bug when audio device ID is empty string.

chromecast/media/service/cast_renderer.cc

 // Copyright 2016 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 "chromecast/media/service/cast_renderer.h"
 
 #include "base/bind.h"
 #include "base/single_thread_task_runner.h"
 #include "chromecast/base/task_runner_impl.h"
 #include "chromecast/media/base/audio_device_ids.h"
@@ skipping 44 matching lines @@
 
 CastRenderer::CastRenderer(
     MediaPipelineBackendFactory* backend_factory,
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
     const std::string& audio_device_id,
     VideoModeSwitcher* video_mode_switcher,
     VideoResolutionPolicy* video_resolution_policy,
     MediaResourceTracker* media_resource_tracker)
     : backend_factory_(backend_factory),
       task_runner_(task_runner),
-      audio_device_id_(audio_device_id),
+      audio_device_id_(audio_device_id.empty()
+                           ? ::media::AudioDeviceDescription::kDefaultDeviceId
+                           : audio_device_id),
       video_mode_switcher_(video_mode_switcher),
       video_resolution_policy_(video_resolution_policy),
       media_resource_tracker_(media_resource_tracker),
       client_(nullptr),
       cast_cdm_context_(nullptr),
       media_task_runner_factory_(
           new BalancedMediaTaskRunnerFactory(kMaxDeltaFetcher)),
       weak_factory_(this) {
   DCHECK(backend_factory_);
   CMALOG(kLogControl) << __FUNCTION__ << ": " << this;
@@ skipping 19 matching lines @@
   // Create pipeline backend.
   media_resource_usage_.reset(
       new MediaResourceTracker::ScopedUsage(media_resource_tracker_));
   backend_task_runner_.reset(new TaskRunnerImpl());
   // TODO(erickung): crbug.com/443956. Need to provide right LoadType.
   LoadType load_type = kLoadTypeMediaSource;
   MediaPipelineDeviceParams::MediaSyncType sync_type =
       (load_type == kLoadTypeMediaStream)
           ? MediaPipelineDeviceParams::kModeIgnorePts
           : MediaPipelineDeviceParams::kModeSyncPts;
-  std::string device_id = audio_device_id_;
-  if (device_id == "")
-    device_id = ::media::AudioDeviceDescription::kDefaultDeviceId;
 
   AudioContentType content_type;
-  if (device_id == kAlarmAudioDeviceId) {
+  if (audio_device_id_ == kAlarmAudioDeviceId) {
     content_type = AudioContentType::kAlarm;
   } else if (audio_device_id_ == kTtsAudioDeviceId) {
     content_type = AudioContentType::kCommunication;
   } else {
     content_type = AudioContentType::kMedia;
   }
   MediaPipelineDeviceParams params(sync_type, backend_task_runner_.get(),
                                    content_type, audio_device_id_);
 
   if (audio_device_id_ == kTtsAudioDeviceId ||
@@ skipping 228 matching lines @@
 }
 
 void CastRenderer::OnVideoOpacityChange(bool opaque) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(opaque);
   client_->OnVideoOpacityChange(opaque);
 }
 
 }  // namespace media
 }  // namespace chromecast