Experimental: Unmute Audio During Tab Sourced Desktop Share

content/browser/media/capture/audio_mirroring_manager.cc

Index: content/browser/media/capture/audio_mirroring_manager.cc
diff --git a/content/browser/media/capture/audio_mirroring_manager.cc b/content/browser/media/capture/audio_mirroring_manager.cc
index f8b8b3a5b183e9d1b1ff07dd6728279b368d0c88..0fbd07cb4647d56c0b9982d5f6f397e72b6b7217 100644
--- a/content/browser/media/capture/audio_mirroring_manager.cc
+++ b/content/browser/media/capture/audio_mirroring_manager.cc
@@ -81,9 +81,24 @@ void AudioMirroringManager::StartMirroring(MirroringDestination* destination) {
     sessions_.push_back(destination);
   }
 
+  std::set<SourceFrameRef> candidates;
+  if (destination->IsDuplication()) {
+    for (StreamRoutes::const_iterator it = routes_.begin(); it != routes_.end();
+         ++it) {
+      if (it->dup_destinations.count(destination) == 0)
+        candidates.insert(it->source_render_frame);
+    }
+    if (!candidates.empty()) {
+      destination->QueryForMatches(
+          candidates,
+          base::Bind(&AudioMirroringManager::UpdateRoutesToDupDestination,
+                     base::Unretained(this), destination, false));
+    }
+    return;
+  }
+
   // Query the MirroringDestination to see which of the audio streams should be
   // diverted.
-  std::set<SourceFrameRef> candidates;
   for (StreamRoutes::const_iterator it = routes_.begin(); it != routes_.end();
        ++it) {
     if (!it->destination || it->destination == destination)
@@ -102,18 +117,24 @@ void AudioMirroringManager::StartMirroring(MirroringDestination* destination) {
 void AudioMirroringManager::StopMirroring(MirroringDestination* destination) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  // Stop diverting each audio stream in the mirroring session being stopped.
-  // Each stopped stream becomes a candidate to be diverted to another
-  // destination.
-  std::set<SourceFrameRef> redivert_candidates;
-  for (StreamRoutes::iterator it = routes_.begin(); it != routes_.end(); ++it) {
-    if (it->destination == destination) {
-      ChangeRoute(&(*it), NULL);
-      redivert_candidates.insert(it->source_render_frame);
+  if (destination->IsDuplication()) {
+    std::set<SourceFrameRef> matches;
+    UpdateRoutesToDupDestination(destination, false, matches);
+  } else {
+    // Stop diverting each audio stream in the mirroring session being stopped.
+    // Each stopped stream becomes a candidate to be diverted to another
+    // destination.
+    std::set<SourceFrameRef> redivert_candidates;
+    for (StreamRoutes::iterator it = routes_.begin(); it != routes_.end();
+         ++it) {
+      if (it->destination == destination) {
+        ChangeRoute(&(*it), NULL);
+        redivert_candidates.insert(it->source_render_frame);
+      }
     }
+    if (!redivert_candidates.empty())
+      InitiateQueriesToFindNewDestination(destination, redivert_candidates);
   }
-  if (!redivert_candidates.empty())
-    InitiateQueriesToFindNewDestination(destination, redivert_candidates);
 
   // Remove the entry from the set of active mirroring sessions.
   const Destinations::iterator dest_it =
@@ -132,7 +153,14 @@ void AudioMirroringManager::InitiateQueriesToFindNewDestination(
 
   for (Destinations::const_iterator it = sessions_.begin();
        it != sessions_.end(); ++it) {
-    if (*it != old_destination) {
+    if (*it == old_destination)
+      continue;
+    if ((*it)->IsDuplication()) {
+      (*it)->QueryForMatches(
+          candidates,
+          base::Bind(&AudioMirroringManager::UpdateRoutesToDupDestination,
+                     base::Unretained(this), *it, true));
+    } else {
       (*it)->QueryForMatches(
           candidates,
           base::Bind(&AudioMirroringManager::UpdateRoutesToDestination,
@@ -177,6 +205,34 @@ void AudioMirroringManager::UpdateRoutesToDestination(
     InitiateQueriesToFindNewDestination(destination, redivert_candidates);
 }
 
+void AudioMirroringManager::UpdateRoutesToDupDestination(
+    MirroringDestination* destination,
+    bool add_only,
+    const std::set<SourceFrameRef>& matches) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (std::find(sessions_.begin(), sessions_.end(), destination) ==
+      sessions_.end()) {
+    return;  // Query result callback invoked after StopMirroring().
+  }
+
+  for (StreamRoutes::iterator it = routes_.begin(); it != routes_.end(); ++it) {
+    if (matches.find(it->source_render_frame) != matches.end()) {
+      if (it->dup_destinations.count(destination) == 0) {
+        it->dup_destinations[destination] =
+            destination->AddPushInput(it->diverter->GetAudioParameters());
+        it->diverter->StartDuplicating(it->dup_destinations[destination]);
+      }
+
+    } else if (!add_only) {
+      if (it->dup_destinations.count(destination) > 0) {
+        it->diverter->StopDuplicating(it->dup_destinations[destination]);
+        it->dup_destinations.erase(destination);
+      }
+    }
+  }
+}
+
 // static
 void AudioMirroringManager::ChangeRoute(
     StreamRoutingState* route, MirroringDestination* new_destination) {