Caching AudioOutputDevice instances in mixer manager

media/renderers/audio_renderer_impl_unittest.cc

Index: media/renderers/audio_renderer_impl_unittest.cc
diff --git a/media/renderers/audio_renderer_impl_unittest.cc b/media/renderers/audio_renderer_impl_unittest.cc
index ce199235950578ce942d218e500d7fccc580b3f4..b00d590585b03b6675af6cd19293b79c3fdc7d48 100644
--- a/media/renderers/audio_renderer_impl_unittest.cc
+++ b/media/renderers/audio_renderer_impl_unittest.cc
@@ -15,7 +15,6 @@
 #include "base/strings/stringprintf.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "media/base/audio_buffer_converter.h"
-#include "media/base/audio_hardware_config.h"
 #include "media/base/audio_splicer.h"
 #include "media/base/fake_audio_renderer_sink.h"
 #include "media/base/gmock_callback_support.h"
@@ -69,7 +68,12 @@ class AudioRendererImplTest : public ::testing::Test, public RendererClient {
  public:
   // Give the decoder some non-garbage media properties.
   AudioRendererImplTest()
-      : hardware_config_(AudioParameters(), AudioParameters()),
+      : hardware_params_(AudioParameters::AUDIO_PCM_LOW_LATENCY,
+                         kChannelLayout,
+                         kOutputSamplesPerSecond,
+                         SampleFormatToBytesPerChannel(kSampleFormat) * 8,
+                         512),
+        sink_(new FakeAudioRendererSink(hardware_params_)),
         tick_clock_(new base::SimpleTestTickClock()),
         demuxer_stream_(DemuxerStream::AUDIO),
         decoder_(new MockAudioDecoder()),
@@ -96,13 +100,11 @@ class AudioRendererImplTest : public ::testing::Test, public RendererClient {
                                kOutputSamplesPerSecond,
                                SampleFormatToBytesPerChannel(kSampleFormat) * 8,
                                512);
-    hardware_config_.UpdateOutputConfig(out_params);
     ScopedVector<AudioDecoder> decoders;
     decoders.push_back(decoder_);
-    sink_ = new FakeAudioRendererSink();
     renderer_.reset(new AudioRendererImpl(message_loop_.task_runner(),
                                           sink_.get(), std::move(decoders),
-                                          hardware_config_, new MediaLog()));
+                                          new MediaLog()));
     renderer_->tick_clock_.reset(tick_clock_);
     tick_clock_->Advance(base::TimeDelta::FromSeconds(1));
   }
@@ -362,10 +364,10 @@ class AudioRendererImplTest : public ::testing::Test, public RendererClient {
   bool ended() const { return ended_; }
 
   // Fixture members.
+  AudioParameters hardware_params_;
   base::MessageLoop message_loop_;
   std::unique_ptr<AudioRendererImpl> renderer_;
   scoped_refptr<FakeAudioRendererSink> sink_;
-  AudioHardwareConfig hardware_config_;
   base::SimpleTestTickClock* tick_clock_;
   PipelineStatistics last_statistics_;
 
@@ -715,16 +717,15 @@ TEST_F(AudioRendererImplTest, RenderingDelayedForEarlyStartTime) {
   // Choose a first timestamp a few buffers into the future, which ends halfway
   // through the desired output buffer; this allows for maximum test coverage.
   const double kBuffers = 4.5;
-  const base::TimeDelta first_timestamp = base::TimeDelta::FromSecondsD(
-      hardware_config_.GetOutputBufferSize() * kBuffers /
-      hardware_config_.GetOutputSampleRate());
+  const base::TimeDelta first_timestamp =
+      base::TimeDelta::FromSecondsD(hardware_params_.frames_per_buffer() *
+                                    kBuffers / hardware_params_.sample_rate());
 
   Preroll(base::TimeDelta(), first_timestamp, PIPELINE_OK);
   StartTicking();
 
   // Verify the first few buffers are silent.
-  std::unique_ptr<AudioBus> bus =
-      AudioBus::Create(hardware_config_.GetOutputConfig());
+  std::unique_ptr<AudioBus> bus = AudioBus::Create(hardware_params_);
   int frames_read = 0;
   for (int i = 0; i < std::floor(kBuffers); ++i) {
     EXPECT_TRUE(sink_->Render(bus.get(), 0, &frames_read));