Experimental: Unmute Audio During Tab Sourced Desktop Share

media/audio/audio_output_controller.cc

Index: media/audio/audio_output_controller.cc
diff --git a/media/audio/audio_output_controller.cc b/media/audio/audio_output_controller.cc
index d780687d1b8415aee8f6223be8497905a80b8800..4262f69f46971aa114aff009d463838c9f8325e5 100644
--- a/media/audio/audio_output_controller.cc
+++ b/media/audio/audio_output_controller.cc
@@ -119,7 +119,8 @@ void AudioOutputController::DoCreate(bool is_for_device_change) {
   if (state_ == kClosed)
     return;
 
-  DoStopCloseAndClearStream();  // Calls RemoveOutputDeviceChangeListener().
+  DoStopCloseAndClearStream(
+      is_for_device_change);  // Calls RemoveOutputDeviceChangeListener().
   DCHECK_EQ(kEmpty, state_);
 
   stream_ = diverting_to_stream_ ?
@@ -132,7 +133,7 @@ void AudioOutputController::DoCreate(bool is_for_device_change) {
   }
 
   if (!stream_->Open()) {
-    DoStopCloseAndClearStream();
+    DoStopCloseAndClearStream(false);
     state_ = kError;
     handler_->OnError();
     return;
@@ -169,6 +170,9 @@ void AudioOutputController::DoPlay() {
   state_ = kPlaying;
 
   stream_->Start(this);
+  for (auto& item : duplicator_) {
+    item->Start();
+  }
 
   // For UMA tracking purposes, start the wedge detection timer.  This allows us
   // to record statistics about the number of wedged playbacks in the field.
@@ -196,6 +200,9 @@ void AudioOutputController::StopStream() {
     wedge_timer_.reset();
     stream_->Stop();
 
+    for (auto& item : duplicator_) {
+      item->Stop();
+    }
     // A stopped stream is silent, and power_montior_.Scan() is no longer being
     // called; so we must reset the power monitor.
     power_monitor_.Reset();
@@ -228,7 +235,7 @@ void AudioOutputController::DoClose() {
   TRACE_EVENT0("audio", "AudioOutputController::DoClose");
 
   if (state_ != kClosed) {
-    DoStopCloseAndClearStream();
+    DoStopCloseAndClearStream(false);
     sync_reader_->Close();
     state_ = kClosed;
   }
@@ -304,6 +311,9 @@ int AudioOutputController::OnMoreData(AudioBus* dest,
   if (will_monitor_audio_levels())
     power_monitor_.Scan(*dest, frames);
 
+  for (auto sink : duplicator_)
+    sink->OnData(nullptr, dest, total_bytes_delay, 1);
+
   return frames;
 }
 
@@ -319,7 +329,7 @@ void AudioOutputController::OnError(AudioOutputStream* stream) {
       &AudioOutputController::DoReportError, this));
 }
 
-void AudioOutputController::DoStopCloseAndClearStream() {
+void AudioOutputController::DoStopCloseAndClearStream(bool isForDeviceChange) {
   DCHECK(message_loop_->BelongsToCurrentThread());
 
   // Allow calling unconditionally and bail if we don't have a stream_ to close.
@@ -336,6 +346,11 @@ void AudioOutputController::DoStopCloseAndClearStream() {
 
     StopStream();
     stream_->Close();
+    if (!isForDeviceChange) {
+      for (auto& item : duplicator_) {
+        item->Close();
+      }
+    }
     if (stream_ == diverting_to_stream_)
       diverting_to_stream_ = NULL;
     stream_ = NULL;
@@ -392,6 +407,18 @@ void AudioOutputController::StopDiverting() {
       FROM_HERE, base::Bind(&AudioOutputController::DoStopDiverting, this));
 }
 
+void AudioOutputController::StartDuplicating(AudioPushSink* to_stream) {
+  message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&AudioOutputController::DoStartDuplicating, this, to_stream));
+}
+
+void AudioOutputController::StopDuplicating(AudioPushSink* to_stream) {
+  message_loop_->PostTask(
+      FROM_HERE,
+      base::Bind(&AudioOutputController::DoStopDuplicating, this, to_stream));
+}
+
 void AudioOutputController::DoStartDiverting(AudioOutputStream* to_stream) {
   DCHECK(message_loop_->BelongsToCurrentThread());
 
@@ -419,6 +446,36 @@ void AudioOutputController::DoStopDiverting() {
   DCHECK(!diverting_to_stream_);
 }
 
+void AudioOutputController::DoStartDuplicating(AudioPushSink* to_stream) {
+  DCHECK(message_loop_->BelongsToCurrentThread());
+  printf("StartDup\n");
+  if (state_ == kClosed)
+    return;
+
+  // Already serving the stream.
+  if (duplicator_.find(to_stream) != duplicator_.end())
+    return;
+
+  duplicator_.insert(to_stream);
+  if (state_ == kPlaying)
+    to_stream->Start();
+}
+
+void AudioOutputController::DoStopDuplicating(AudioPushSink* to_stream) {
+  DCHECK(message_loop_->BelongsToCurrentThread());
+
+  if (state_ == kClosed)
+    return;
+
+  // No such stream.
+  if (duplicator_.find(to_stream) == duplicator_.end())
+    return;
+
+  to_stream->Stop();
+  to_stream->Close();
+  duplicator_.erase(to_stream);
+}
+
 std::pair<float, bool> AudioOutputController::ReadCurrentPowerAndClip() {
   DCHECK(will_monitor_audio_levels());
   return power_monitor_.ReadCurrentPowerAndClip();