Add play test.

media/audio/mac/audio_low_latency_input_mac_unittest.cc

Index: media/audio/mac/audio_low_latency_input_mac_unittest.cc
diff --git a/media/audio/mac/audio_low_latency_input_mac_unittest.cc b/media/audio/mac/audio_low_latency_input_mac_unittest.cc
index d10bc346300fbe0fb01e6b98fd86ac1ddf49e9c8..6f64fae1493fc5cac0d18d003377a84f8f41fec9 100644
--- a/media/audio/mac/audio_low_latency_input_mac_unittest.cc
+++ b/media/audio/mac/audio_low_latency_input_mac_unittest.cc
@@ -17,6 +17,7 @@
 #include "media/audio/audio_manager_base.h"
 #include "media/audio/audio_unittest_util.h"
 #include "media/audio/mac/audio_low_latency_input_mac.h"
+#include "media/audio/simple_sources.h"
 #include "media/base/seekable_buffer.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -286,4 +287,22 @@ TEST_F(MacAudioInputTest, DISABLED_AUAudioInputStreamRecordToFile) {
   ais->Close();
 }
 
+TEST_F(MacAudioInputTest, AudioOutputTest) {
+  AudioParameters params = audio_manager_->GetDefaultOutputStreamParameters();
+  LOG(ERROR) << "Params: " << params.AsHumanReadableString();
+
+  SineWaveAudioSource source(params.channels(), 440, params.sample_rate());
+  AudioOutputStream* stream =
+      audio_manager_->MakeAudioOutputStreamProxy(params, "");
+  ASSERT_TRUE(stream->Open());
+  stream->Start(&source);
+
+  base::RunLoop run_loop;
+  message_loop_.task_runner()->PostDelayedTask(
+      FROM_HERE, run_loop.QuitClosure(), base::TimeDelta::FromSeconds(5));
+  run_loop.Run();
+  stream->Stop();
+  stream->Close();
+}
+
 }  // namespace media