Purge AudioOutputDispatcherImpl's idle stream cache on device change.

Since default device is always matched as an empty string, we would
sometimes reconnect to a stream which was configured for the wrong
device.

R=guidou

Bug: 1091894
Change-Id: Ia3a33d8f91d984de5ceffbcbb4ddd96efed355e1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2468302
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Auto-Submit: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816749}

media/audio/audio_output_dispatcher_impl.cc

@@ -33,6 +33,7 @@ AudioOutputDispatcherImpl::AudioOutputDispatcherImpl(
                    &AudioOutputDispatcherImpl::CloseAllIdleStreams),
       audio_stream_id_(0) {
   DCHECK(audio_manager->GetTaskRunner()->BelongsToCurrentThread());
+  audio_manager->AddOutputDeviceChangeListener(this);
 }
 
 AudioOutputDispatcherImpl::~AudioOutputDispatcherImpl() {
@@ -47,6 +48,8 @@ AudioOutputDispatcherImpl::~AudioOutputDispatcherImpl() {
   // invalidating any outstanding tasks upon its destruction.
   CloseAllIdleStreams();
 
+  audio_manager()->RemoveOutputDeviceChangeListener(this);
+
   // All idle physical streams must have been closed during shutdown.
   CHECK(idle_streams_.empty());
 }
@@ -134,6 +137,17 @@ void AudioOutputDispatcherImpl::CloseStream(AudioOutputProxy* stream_proxy) {
 // StopStream().
 void AudioOutputDispatcherImpl::FlushStream(AudioOutputProxy* stream_proxy) {}
 
+void AudioOutputDispatcherImpl::OnDeviceChange() {
+  DCHECK(audio_manager()->GetTaskRunner()->BelongsToCurrentThread());
+
+  // We don't want to end up reusing streams which were opened for the wrong
+  // default device. We need to post this task so it runs after device changes
+  // have been sent to all listeners and they've had time to close streams.
+  audio_manager()->GetTaskRunner()->PostTask(
+      FROM_HERE, base::BindOnce(&AudioOutputDispatcherImpl::CloseAllIdleStreams,
+                                weak_factory_.GetWeakPtr()));
+}
+
 bool AudioOutputDispatcherImpl::HasOutputProxies() const {
   DCHECK(audio_manager()->GetTaskRunner()->BelongsToCurrentThread());
   return idle_proxies_ || !proxy_to_physical_map_.empty();

media/audio/audio_output_dispatcher_impl.h

@@ -23,13 +23,16 @@
 #include "base/macros.h"
 #include "base/timer/timer.h"
 #include "media/audio/audio_io.h"
+#include "media/audio/audio_manager.h"
 #include "media/audio/audio_output_dispatcher.h"
 #include "media/base/audio_parameters.h"
 
 namespace media {
 class AudioLog;
 
-class MEDIA_EXPORT AudioOutputDispatcherImpl : public AudioOutputDispatcher {
+class MEDIA_EXPORT AudioOutputDispatcherImpl
+    : public AudioOutputDispatcher,
+      public AudioManager::AudioDeviceListener {
  public:
   // |close_delay| specifies delay after the stream is idle until the audio
   // device is closed.
@@ -49,6 +52,9 @@ class MEDIA_EXPORT AudioOutputDispatcherImpl : public AudioOutputDispatcher {
   void CloseStream(AudioOutputProxy* stream_proxy) override;
   void FlushStream(AudioOutputProxy* stream_proxy) override;
 
+  // AudioDeviceListener implementation.
+  void OnDeviceChange() override;
+
   // Returns true if there are any open AudioOutputProxy objects.
   bool HasOutputProxies() const;
 

media/audio/audio_output_proxy_unittest.cc

@@ -640,6 +640,32 @@ TEST_F(AudioOutputResamplerTest, DispatcherDestroyed_AfterStop) {
   DispatcherDestroyed_AfterStop(std::move(resampler_));
 }
 
+TEST_F(AudioOutputProxyTest, DispatcherDeviceChangeClosesIdleStreams) {
+  // Set close delay so long that it triggers a test timeout if relied upon.
+  InitDispatcher(base::TimeDelta::FromSeconds(1000));
+
+  MockAudioOutputStream stream(&manager_, params_);
+
+  EXPECT_CALL(manager(), MakeAudioOutputStream(_, _, _))
+      .WillOnce(Return(&stream));
+  EXPECT_CALL(stream, Open()).WillOnce(Return(true));
+
+  AudioOutputProxy* proxy = dispatcher_impl_->CreateStreamProxy();
+  EXPECT_TRUE(proxy->Open());
+
+  // Close the stream and verify it doesn't happen immediately.
+  proxy->Close();
+  Mock::VerifyAndClear(&stream);
+
+  // This should trigger a true close on the stream.
+  dispatcher_impl_->OnDeviceChange();
+
+  base::RunLoop run_loop;
+  EXPECT_CALL(stream, Close())
+      .WillOnce(testing::InvokeWithoutArgs(&run_loop, &base::RunLoop::Quit));
+  run_loop.Run();
+}
+
 // Simulate AudioOutputStream::Create() failure with a low latency stream and
 // ensure AudioOutputResampler falls back to the high latency path.
 TEST_F(AudioOutputResamplerTest, LowLatencyCreateFailedFallback) {